PKGBUILDs/extra/qt5-webengine/qt5-webengine-chromium-python3.patch

diff --git a/chromium/components/resources/protobufs/binary_proto_generator.py b/chromium/components/resources/protobufs/binary_proto_generator.py
index 7422ead9697..16365515f26 100755
--- a/chromium/components/resources/protobufs/binary_proto_generator.py
+++ b/chromium/components/resources/protobufs/binary_proto_generator.py
@@ -7,7 +7,7 @@
  Converts a given ASCII proto into a binary resource.
 
 """
-
+from __future__ import print_function
 import abc
 import imp
 import optparse
@@ -196,12 +196,12 @@ class BinaryProtoGenerator:
     self._ImportProtoModules(opts.path)
 
     if not self.VerifyArgs(opts):
-      print "Wrong arguments"
+      print("Wrong arguments")
       return 1
 
     try:
       self._GenerateBinaryProtos(opts)
     except Exception as e:
-      print "ERROR: Failed to render binary version of %s:\n  %s\n%s" % (
-          opts.infile, str(e), traceback.format_exc())
+      print("ERROR: Failed to render binary version of %s:\n  %s\n%s" %
+            (opts.infile, str(e), traceback.format_exc()))
       return 1
diff --git a/chromium/content/browser/tracing/generate_trace_viewer_grd.py b/chromium/content/browser/tracing/generate_trace_viewer_grd.py
index 037f9497dc2..be393d21f90 100755
--- a/chromium/content/browser/tracing/generate_trace_viewer_grd.py
+++ b/chromium/content/browser/tracing/generate_trace_viewer_grd.py
@@ -74,7 +74,7 @@ def main(argv):
   for filename in parsed_args.source_files:
     add_file_to_grd(doc, os.path.basename(filename))
 
-  with open(parsed_args.output_filename, 'w') as output_file:
+  with open(parsed_args.output_filename, 'wb') as output_file:
     output_file.write(doc.toxml(encoding='UTF-8'))
 
 
diff --git a/chromium/mojo/public/tools/bindings/BUILD.gn b/chromium/mojo/public/tools/bindings/BUILD.gn
index fc04b5dd0b1..708958e438b 100644
--- a/chromium/mojo/public/tools/bindings/BUILD.gn
+++ b/chromium/mojo/public/tools/bindings/BUILD.gn
@@ -2,9 +2,11 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/python.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/jinja2/jinja2.gni")
 
+# TODO(crbug.com/1194274): Investigate nondeterminism in Py3 builds.
 action("precompile_templates") {
   sources = mojom_generator_sources
   sources += [
diff --git a/chromium/mojo/public/tools/bindings/gen_data_files_list.py b/chromium/mojo/public/tools/bindings/gen_data_files_list.py
index 79c9e50efce..8b78d092418 100644
--- a/chromium/mojo/public/tools/bindings/gen_data_files_list.py
+++ b/chromium/mojo/public/tools/bindings/gen_data_files_list.py
@@ -18,7 +18,6 @@ import os
 import re
 import sys
 
-from cStringIO import StringIO
 from optparse import OptionParser
 
 sys.path.insert(
@@ -41,12 +40,9 @@ def main():
   pattern = re.compile(options.pattern)
   files = [f for f in os.listdir(options.directory) if pattern.match(f)]
 
-  stream = StringIO()
-  for f in files:
-    print(f, file=stream)
+  contents = '\n'.join(f for f in files) + '\n'
+  WriteFile(contents, options.output)
 
-  WriteFile(stream.getvalue(), options.output)
-  stream.close()
 
 if __name__ == '__main__':
   sys.exit(main())
diff --git a/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py b/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py
index 96b2fdfae0c..00b9dccd00c 100644
--- a/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py
+++ b/chromium/mojo/public/tools/bindings/generators/mojom_java_generator.py
@@ -25,6 +25,10 @@ sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir,
                              'build', 'android', 'gyp'))
 from util import build_utils
 
+# TODO(crbug.com/1174969): Remove this once Python2 is obsoleted.
+if sys.version_info.major != 2:
+  basestring = str
+  long = int
 
 GENERATOR_PREFIX = 'java'
 
diff --git a/chromium/mojo/public/tools/mojom/mojom/generate/generator.py b/chromium/mojo/public/tools/mojom/mojom/generate/generator.py
index de62260a5c9..4a1c73fcf82 100644
--- a/chromium/mojo/public/tools/mojom/mojom/generate/generator.py
+++ b/chromium/mojo/public/tools/mojom/mojom/generate/generator.py
@@ -136,9 +136,14 @@ class Stylizer(object):
 
 def WriteFile(contents, full_path):
   # If |contents| is same with the file content, we skip updating.
+  if not isinstance(contents, bytes):
+    data = contents.encode('utf8')
+  else:
+    data = contents
+
   if os.path.isfile(full_path):
     with open(full_path, 'rb') as destination_file:
-      if destination_file.read() == contents:
+      if destination_file.read() == data:
         return
 
   # Make sure the containing directory exists.
@@ -146,11 +151,8 @@ def WriteFile(contents, full_path):
   fileutil.EnsureDirectoryExists(full_dir)
 
   # Dump the data to disk.
-  with open(full_path, "wb") as f:
-    if not isinstance(contents, bytes):
-      f.write(contents.encode('utf-8'))
-    else:
-      f.write(contents)
+  with open(full_path, 'wb') as f:
+    f.write(data)
 
 
 def AddComputedData(module):
diff --git a/chromium/mojo/public/tools/mojom/mojom/generate/module.py b/chromium/mojo/public/tools/mojom/mojom/generate/module.py
index ebbc9b322ea..3d026429bbc 100644
--- a/chromium/mojo/public/tools/mojom/mojom/generate/module.py
+++ b/chromium/mojo/public/tools/mojom/mojom/generate/module.py
@@ -398,7 +398,8 @@ class Field(object):
 
 
 class StructField(Field):
-  pass
+  def __hash__(self):
+    return super(Field, self).__hash__()
 
 
 class UnionField(Field):
diff --git a/chromium/mojo/public/tools/mojom/mojom/generate/template_expander.py b/chromium/mojo/public/tools/mojom/mojom/generate/template_expander.py
index 7a300560246..8d9e26fb7f6 100644
--- a/chromium/mojo/public/tools/mojom/mojom/generate/template_expander.py
+++ b/chromium/mojo/public/tools/mojom/mojom/generate/template_expander.py
@@ -75,9 +75,9 @@ def PrecompileTemplates(generator_modules, output_dir):
                 os.path.dirname(module.__file__), generator.GetTemplatePrefix())
         ]))
     jinja_env.filters.update(generator.GetFilters())
-    jinja_env.compile_templates(
-        os.path.join(output_dir, "%s.zip" % generator.GetTemplatePrefix()),
-        extensions=["tmpl"],
-        zip="stored",
-        py_compile=True,
-        ignore_errors=False)
+    jinja_env.compile_templates(os.path.join(
+        output_dir, "%s.zip" % generator.GetTemplatePrefix()),
+                                extensions=["tmpl"],
+                                zip="stored",
+                                py_compile=sys.version_info.major < 3,
+                                ignore_errors=False)
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/blink_v8_bridge.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/blink_v8_bridge.py
index 3225ecca6e4..fc078d31b55 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/blink_v8_bridge.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/blink_v8_bridge.py
@@ -344,7 +344,7 @@ def make_default_value_expr(idl_type, default_value):
     """
     assert default_value.is_type_compatible_with(idl_type)
 
-    class DefaultValueExpr:
+    class DefaultValueExpr(object):
         _ALLOWED_SYMBOLS_IN_DEPS = ("isolate")
 
         def __init__(self, initializer_expr, initializer_deps,
@@ -502,7 +502,7 @@ def make_v8_to_blink_value(blink_var_name,
     assert isinstance(blink_var_name, str)
     assert isinstance(v8_value_expr, str)
     assert isinstance(idl_type, web_idl.IdlType)
-    assert (argument_index is None or isinstance(argument_index, (int, long)))
+    assert (argument_index is None or isinstance(argument_index, int))
     assert (default_value is None
             or isinstance(default_value, web_idl.LiteralConstant))
 
@@ -622,7 +622,7 @@ def make_v8_to_blink_value_variadic(blink_var_name, v8_array,
     """
     assert isinstance(blink_var_name, str)
     assert isinstance(v8_array, str)
-    assert isinstance(v8_array_start_index, (int, long))
+    assert isinstance(v8_array_start_index, int)
     assert isinstance(idl_type, web_idl.IdlType)
 
     pattern = ("auto&& ${{{_1}}} = "
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/callback_interface.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/callback_interface.py
index 4a6df513068..8b51f23a409 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/callback_interface.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/callback_interface.py
@@ -177,7 +177,7 @@ def generate_callback_interface(callback_interface_identifier):
          prop_install_mode=PropInstallMode.UNCONDITIONAL,
          trampoline_var_name=None,
          attribute_entries=[],
-         constant_entries=filter(is_unconditional, constant_entries),
+         constant_entries=list(filter(is_unconditional, constant_entries)),
          exposed_construct_entries=[],
          operation_entries=[])
     (install_interface_template_decl, install_interface_template_def,
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/code_node.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/code_node.py
index 52972fefe20..e5ae9d9629e 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/code_node.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/code_node.py
@@ -503,13 +503,13 @@ class CompositeNode(CodeNode):
         gensym_kwargs = {}
         template_vars = {}
         for arg in args:
-            assert isinstance(arg, (CodeNode, int, long, str))
+            assert isinstance(arg, (CodeNode, int, str))
             gensym = CodeNode.gensym()
             gensym_args.append("${{{}}}".format(gensym))
             template_vars[gensym] = arg
         for key, value in kwargs.items():
-            assert isinstance(key, (int, long, str))
-            assert isinstance(value, (CodeNode, int, long, str))
+            assert isinstance(key, (int, str))
+            assert isinstance(value, (CodeNode, int, str))
             gensym = CodeNode.gensym()
             gensym_kwargs[key] = "${{{}}}".format(gensym)
             template_vars[gensym] = value
@@ -602,7 +602,7 @@ class ListNode(CodeNode):
     def insert(self, index, node):
         if node is None:
             return
-        assert isinstance(index, (int, long))
+        assert isinstance(index, int)
         assert isinstance(node, CodeNode)
         assert node.outer is None and node.prev is None
 
@@ -721,7 +721,7 @@ class SymbolScopeNode(SequenceNode):
             if not scope_chains:
                 return counts
 
-            self_index = iter(scope_chains).next().index(self)
+            self_index = next(iter(scope_chains)).index(self)
             scope_chains = map(
                 lambda scope_chain: scope_chain[self_index + 1:], scope_chains)
             scope_to_likeliness = {}
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_expr.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_expr.py
index a229a6c71c9..5fa288dabf2 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_expr.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_expr.py
@@ -109,7 +109,7 @@ def expr_and(terms):
 
     if any(term.is_always_false for term in terms):
         return _Expr(False)
-    terms = filter(lambda x: not x.is_always_true, terms)
+    terms = list(filter(lambda x: not x.is_always_true, terms))
     if not terms:
         return _Expr(True)
     if len(terms) == 1:
@@ -124,7 +124,7 @@ def expr_or(terms):
 
     if any(term.is_always_true for term in terms):
         return _Expr(True)
-    terms = filter(lambda x: not x.is_always_false, terms)
+    terms = list(filter(lambda x: not x.is_always_false, terms))
     if not terms:
         return _Expr(False)
     if len(terms) == 1:
@@ -222,7 +222,7 @@ def expr_from_exposure(exposure,
     elif exposure.only_in_secure_contexts is False:
         secure_context_term = _Expr(True)
     else:
-        terms = map(ref_enabled, exposure.only_in_secure_contexts)
+        terms = list(map(ref_enabled, exposure.only_in_secure_contexts))
         secure_context_term = expr_or(
             [_Expr("${is_in_secure_context}"),
              expr_not(expr_and(terms))])
@@ -275,10 +275,11 @@ def expr_from_exposure(exposure,
 
     # [ContextEnabled]
     if exposure.context_enabled_features:
-        terms = map(
-            lambda feature: _Expr(
-                "${{context_feature_settings}}->is{}Enabled()".format(
-                    feature)), exposure.context_enabled_features)
+        terms = list(
+            map(
+                lambda feature: _Expr(
+                    "${{context_feature_settings}}->is{}Enabled()".format(
+                        feature)), exposure.context_enabled_features))
         context_enabled_terms.append(
             expr_and([_Expr("${context_feature_settings}"),
                       expr_or(terms)]))
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_format.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_format.py
index 87d26eec3ca..f3e9d38247e 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_format.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_format.py
@@ -23,7 +23,7 @@ class _TemplateFormatter(string.Formatter):
         self._template_formatter_indexing_count_ = 0
 
     def get_value(self, key, args, kwargs):
-        if isinstance(key, (int, long)):
+        if isinstance(key, int):
             return args[key]
         assert isinstance(key, str)
         if not key:
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_utils.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_utils.py
index 2bcc4fed49a..e72282aa696 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_utils.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/codegen_utils.py
@@ -116,4 +116,4 @@ def write_code_node_to_file(code_node, filepath):
 #                               stderr=format_result.error_message))
 #
 #    web_idl.file_io.write_to_file_if_changed(filepath, format_result.contents)
-    web_idl.file_io.write_to_file_if_changed(filepath, rendered_text)
+    web_idl.file_io.write_to_file_if_changed(filepath, rendered_text.encode('utf-8'))
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/dictionary.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/dictionary.py
index b39f0100410..4d68202296b 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/dictionary.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/dictionary.py
@@ -993,7 +993,7 @@ def make_dict_trace_func(cg_context):
         _2 = _blink_member_name(member).value_var
         return TextNode(_format(pattern, _1=_1, _2=_2))
 
-    body.extend(map(make_trace_member_node, own_members))
+    body.extend(list(map(make_trace_member_node, own_members)))
     body.append(TextNode("BaseClass::Trace(visitor);"))
 
     return func_decl, func_def
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/interface.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/interface.py
index 10ff30656ad..bfdf7128aac 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/interface.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/interface.py
@@ -582,7 +582,7 @@ def _make_blink_api_call(code_node,
                          overriding_args=None):
     assert isinstance(code_node, SymbolScopeNode)
     assert isinstance(cg_context, CodeGenContext)
-    assert num_of_args is None or isinstance(num_of_args, (int, long))
+    assert num_of_args is None or isinstance(num_of_args, int)
     assert (overriding_args is None
             or (isinstance(overriding_args, (list, tuple))
                 and all(isinstance(arg, str) for arg in overriding_args)))
@@ -1196,8 +1196,10 @@ def make_overload_dispatcher(cg_context):
             did_use_break = did_use_break or can_fail
 
         conditional = expr_or(
-            map(lambda item: expr_from_exposure(item.function_like.exposure),
-                items))
+            list(
+                map(
+                    lambda item: expr_from_exposure(item.function_like.exposure
+                                                    ), items)))
         if not conditional.is_always_true:
             node = CxxUnlikelyIfNode(cond=conditional, body=node)
 
@@ -4642,7 +4644,7 @@ class _PropEntryConstructorGroup(_PropEntryBase):
     def __init__(self, is_context_dependent, exposure_conditional, world,
                  constructor_group, ctor_callback_name, ctor_func_length):
         assert isinstance(ctor_callback_name, str)
-        assert isinstance(ctor_func_length, (int, long))
+        assert isinstance(ctor_func_length, int)
 
         _PropEntryBase.__init__(self, is_context_dependent,
                                 exposure_conditional, world, constructor_group)
@@ -4670,7 +4672,7 @@ class _PropEntryOperationGroup(_PropEntryBase):
                  op_func_length,
                  no_alloc_direct_callback_name=None):
         assert isinstance(op_callback_name, str)
-        assert isinstance(op_func_length, (int, long))
+        assert isinstance(op_func_length, int)
 
         _PropEntryBase.__init__(self, is_context_dependent,
                                 exposure_conditional, world, operation_group)
@@ -5175,9 +5177,9 @@ def make_install_interface_template(cg_context, function_name, class_name, api_c
     ])
 
     if class_like.identifier == "CSSStyleDeclaration":
-        css_properties = filter(
-            lambda attr: "CSSProperty" in attr.extended_attributes,
-            class_like.attributes)
+        css_properties = list(
+            filter(lambda attr: "CSSProperty" in attr.extended_attributes,
+                   class_like.attributes))
         if css_properties:
             prop_name_list = "".join(
                 map(lambda attr: "\"{}\", ".format(attr.identifier),
@@ -5567,8 +5569,8 @@ ${instance_object} = ${v8_context}->Global()->GetPrototype().As<v8::Object>();\
             "V8DOMConfiguration::InstallConstants(${isolate}, "
             "${interface_template}, ${prototype_template}, "
             "kConstantCallbackTable, base::size(kConstantCallbackTable));")
-    constant_callback_entries = filter(lambda entry: entry.const_callback_name,
-                                       constant_entries)
+    constant_callback_entries = list(filter(lambda entry: entry.const_callback_name,
+                                       constant_entries))
     install_properties(table_name, constant_callback_entries,
                        _make_constant_callback_registration_table,
                        installer_call_text)
@@ -5584,8 +5586,8 @@ ${instance_object} = ${v8_context}->Global()->GetPrototype().As<v8::Object>();\
             "V8DOMConfiguration::InstallConstants(${isolate}, "
             "${interface_template}, ${prototype_template}, "
             "kConstantValueTable, base::size(kConstantValueTable));")
-    constant_value_entries = filter(
-        lambda entry: not entry.const_callback_name, constant_entries)
+    constant_value_entries = list(filter(
+        lambda entry: not entry.const_callback_name, constant_entries))
     install_properties(table_name, constant_value_entries,
                        _make_constant_value_registration_table,
                        installer_call_text)
@@ -6336,8 +6338,8 @@ def make_v8_context_snapshot_api(cg_context, component, attribute_entries,
     assert isinstance(component, web_idl.Component)
 
     derived_interfaces = cg_context.interface.deriveds
-    derived_names = map(lambda interface: interface.identifier,
-                        derived_interfaces)
+    derived_names = list(
+        map(lambda interface: interface.identifier, derived_interfaces))
     derived_names.append(cg_context.interface.identifier)
     if not ("Window" in derived_names or "HTMLDocument" in derived_names):
         return None, None
@@ -6411,9 +6413,11 @@ def _make_v8_context_snapshot_get_reference_table_function(
     collect_callbacks(named_properties_object_callback_defs)
     collect_callbacks(cross_origin_property_callback_defs)
 
-    entry_nodes = map(
-        lambda name: TextNode("reinterpret_cast<intptr_t>({}),".format(name)),
-        filter(None, callback_names))
+    entry_nodes = list(
+        map(
+            lambda name: TextNode("reinterpret_cast<intptr_t>({}),".format(name
+                                                                           )),
+            filter(None, callback_names)))
     table_node = ListNode([
         TextNode("using namespace ${class_name}Callbacks;"),
         TextNode("static const intptr_t kReferenceTable[] = {"),
@@ -6451,10 +6455,11 @@ def _make_v8_context_snapshot_install_props_per_context_function(
         class_name=None,
         prop_install_mode=PropInstallMode.V8_CONTEXT_SNAPSHOT,
         trampoline_var_name=None,
-        attribute_entries=filter(selector, attribute_entries),
-        constant_entries=filter(selector, constant_entries),
-        exposed_construct_entries=filter(selector, exposed_construct_entries),
-        operation_entries=filter(selector, operation_entries))
+        attribute_entries=list(filter(selector, attribute_entries)),
+        constant_entries=list(filter(selector, constant_entries)),
+        exposed_construct_entries=list(
+            filter(selector, exposed_construct_entries)),
+        operation_entries=list(filter(selector, operation_entries)))
 
     return func_decl, func_def
 
@@ -6810,11 +6815,11 @@ def generate_interface(interface_identifier):
          class_name=impl_class_name,
          prop_install_mode=PropInstallMode.UNCONDITIONAL,
          trampoline_var_name=tp_install_unconditional_props,
-         attribute_entries=filter(is_unconditional, attribute_entries),
-         constant_entries=filter(is_unconditional, constant_entries),
-         exposed_construct_entries=filter(is_unconditional,
-                                          exposed_construct_entries),
-         operation_entries=filter(is_unconditional, operation_entries))
+         attribute_entries=list(filter(is_unconditional, attribute_entries)),
+         constant_entries=list(filter(is_unconditional, constant_entries)),
+         exposed_construct_entries=list(
+             filter(is_unconditional, exposed_construct_entries)),
+         operation_entries=list(filter(is_unconditional, operation_entries)))
     (install_context_independent_props_decl,
      install_context_independent_props_def,
      install_context_independent_props_trampoline) = make_install_properties(
@@ -6823,11 +6828,14 @@ def generate_interface(interface_identifier):
          class_name=impl_class_name,
          prop_install_mode=PropInstallMode.CONTEXT_INDEPENDENT,
          trampoline_var_name=tp_install_context_independent_props,
-         attribute_entries=filter(is_context_independent, attribute_entries),
-         constant_entries=filter(is_context_independent, constant_entries),
-         exposed_construct_entries=filter(is_context_independent,
-                                          exposed_construct_entries),
-         operation_entries=filter(is_context_independent, operation_entries))
+         attribute_entries=list(
+             filter(is_context_independent, attribute_entries)),
+         constant_entries=list(filter(is_context_independent,
+                                      constant_entries)),
+         exposed_construct_entries=list(
+             filter(is_context_independent, exposed_construct_entries)),
+         operation_entries=list(
+             filter(is_context_independent, operation_entries)))
     (install_context_dependent_props_decl, install_context_dependent_props_def,
      install_context_dependent_props_trampoline) = make_install_properties(
          cg_context,
@@ -6835,11 +6843,13 @@ def generate_interface(interface_identifier):
          class_name=impl_class_name,
          prop_install_mode=PropInstallMode.CONTEXT_DEPENDENT,
          trampoline_var_name=tp_install_context_dependent_props,
-         attribute_entries=filter(is_context_dependent, attribute_entries),
-         constant_entries=filter(is_context_dependent, constant_entries),
-         exposed_construct_entries=filter(is_context_dependent,
-                                          exposed_construct_entries),
-         operation_entries=filter(is_context_dependent, operation_entries))
+         attribute_entries=list(filter(is_context_dependent,
+                                       attribute_entries)),
+         constant_entries=list(filter(is_context_dependent, constant_entries)),
+         exposed_construct_entries=list(
+             filter(is_context_dependent, exposed_construct_entries)),
+         operation_entries=list(filter(is_context_dependent,
+                                       operation_entries)))
     (install_interface_template_decl, install_interface_template_def,
      install_interface_template_trampoline) = make_install_interface_template(
          cg_context,
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/mako_renderer.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/mako_renderer.py
index b4c70553863..f3a2fcd772d 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/mako_renderer.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/mako_renderer.py
@@ -105,7 +105,7 @@ class MakoRenderer(object):
             on_error = self._caller_stack_on_error
             if (len(current) <= len(on_error)
                     and all(current[i] == on_error[i]
-                            for i in xrange(len(current)))):
+                            for i in range(len(current)))):
                 pass  # Error happened in a deeper caller.
             else:
                 self._caller_stack_on_error = list(self._caller_stack)
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/style_format.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/style_format.py
index dc3493cc394..017d3d47bb3 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/style_format.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/style_format.py
@@ -70,8 +70,13 @@ def gn_format(contents, filename=None):
 
 
 def _invoke_format_command(command_line, filename, contents):
-    proc = subprocess.Popen(
-        command_line, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+    kwargs = {}
+    if sys.version_info.major != 2:
+        kwargs['encoding'] = 'utf-8'
+    proc = subprocess.Popen(command_line,
+                            stdin=subprocess.PIPE,
+                            stdout=subprocess.PIPE,
+                            **kwargs)
     stdout_output, stderr_output = proc.communicate(input=contents)
     exit_code = proc.wait()
 
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/task_queue.py b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/task_queue.py
index 0d8f4c0f303..e666a9b668e 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/task_queue.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/bind_gen/task_queue.py
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import functools
 import multiprocessing
 
 from .package_initializer import package_initializer
@@ -76,7 +77,7 @@ class TaskQueue(object):
         if not report_progress:
             return
 
-        done_count = reduce(
+        done_count = functools.reduce(
             lambda count, worker_task: count + bool(worker_task.ready()),
             self._worker_tasks, 0)
         report_progress(len(self._worker_tasks), done_count)
@@ -85,4 +86,4 @@ class TaskQueue(object):
 def _task_queue_run_tasks(tasks):
     for task in tasks:
         func, args, kwargs = task
-        apply(func, args, kwargs)
+        func(*args, **kwargs)
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/code_generator.py b/chromium/third_party/blink/renderer/bindings/scripts/code_generator.py
index e8280be7213..e49e6eb965e 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/code_generator.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/code_generator.py
@@ -13,6 +13,7 @@ import re
 import sys
 
 from idl_types import set_ancestors, IdlType
+from itertools import groupby
 from v8_globals import includes
 from v8_interface import constant_filters
 from v8_types import set_component_dirs
@@ -43,6 +44,7 @@ TEMPLATES_DIR = os.path.normpath(
 # after path[0] == invoking script dir
 sys.path.insert(1, THIRD_PARTY_DIR)
 import jinja2
+from jinja2.filters import make_attrgetter, environmentfilter
 
 
 def generate_indented_conditional(code, conditional):
@@ -88,6 +90,13 @@ def runtime_enabled_if(code, name):
     return generate_indented_conditional(code, function)
 
 
+@environmentfilter
+def do_stringify_key_group_by(environment, value, attribute):
+    expr = make_attrgetter(environment, attribute)
+    key = lambda item: '' if expr(item) is None else str(expr(item))
+    return groupby(sorted(value, key=key), expr)
+
+
 def initialize_jinja_env(cache_dir):
     jinja_env = jinja2.Environment(
         loader=jinja2.FileSystemLoader(TEMPLATES_DIR),
@@ -117,6 +126,7 @@ def initialize_jinja_env(cache_dir):
     })
     jinja_env.filters.update(constant_filters())
     jinja_env.filters.update(method_filters())
+    jinja_env.filters["stringifykeygroupby"] = do_stringify_key_group_by
     return jinja_env
 
 
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/generate_origin_trial_features.py b/chromium/third_party/blink/renderer/bindings/scripts/generate_origin_trial_features.py
index 130004eae83..04c0fabcef2 100755
--- a/chromium/third_party/blink/renderer/bindings/scripts/generate_origin_trial_features.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/generate_origin_trial_features.py
@@ -80,7 +80,7 @@ def read_idl_file(reader, idl_filename):
     assert len(interfaces) == 1, (
         "Expected one interface in file %r, found %d" %
         (idl_filename, len(interfaces)))
-    return (interfaces.values()[0], includes)
+    return (list(interfaces.values())[0], includes)
 
 
 def interface_is_global(interface):
@@ -281,7 +281,7 @@ def main():
 
     info_provider = create_component_info_provider(
         os.path.normpath(options.info_dir), options.target_component)
-    idl_filenames = map(str.strip, open(options.idl_files_list))
+    idl_filenames = list(map(str.strip, open(options.idl_files_list)))
 
     generate_origin_trial_features(info_provider, options, idl_filenames)
     return 0
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/idl_definitions.py b/chromium/third_party/blink/renderer/bindings/scripts/idl_definitions.py
index 14e6e9d3f87..b027818aef2 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/idl_definitions.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/idl_definitions.py
@@ -394,7 +394,8 @@ class IdlInterface(object):
             else:
                 raise ValueError('Unrecognized node class: %s' % child_class)
 
-        if len(filter(None, [self.iterable, self.maplike, self.setlike])) > 1:
+        if len(list(filter(None,
+                           [self.iterable, self.maplike, self.setlike]))) > 1:
             raise ValueError(
                 'Interface can only have one of iterable<>, maplike<> and setlike<>.'
             )
@@ -512,6 +513,9 @@ class IdlAttribute(TypedObject):
     def accept(self, visitor):
         visitor.visit_attribute(self)
 
+    def __lt__(self, other):
+        return self.name < other.name
+
 
 ################################################################################
 # Constants
@@ -852,7 +856,7 @@ class IdlIncludes(object):
 ################################################################################
 
 
-class Exposure:
+class Exposure(object):
     """An Exposure holds one Exposed or RuntimeEnabled condition.
     Each exposure has two properties: exposed and runtime_enabled.
     Exposure(e, r) corresponds to [Exposed(e r)]. Exposure(e) corresponds to
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/idl_reader.py b/chromium/third_party/blink/renderer/bindings/scripts/idl_reader.py
index 8d72865a6ca..b80eebdcd61 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/idl_reader.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/idl_reader.py
@@ -55,8 +55,8 @@ def validate_blink_idl_definitions(idl_filename, idl_file_basename,
          definitions. There is no filename convention in this case.
        - Otherwise, an IDL file is invalid.
     """
-    targets = (
-        definitions.interfaces.values() + definitions.dictionaries.values())
+    targets = (list(definitions.interfaces.values()) +
+               list(definitions.dictionaries.values()))
     number_of_targets = len(targets)
     if number_of_targets > 1:
         raise Exception(
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/idl_types.py b/chromium/third_party/blink/renderer/bindings/scripts/idl_types.py
index cd4f0c3513b..ab95e9c0b08 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/idl_types.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/idl_types.py
@@ -349,7 +349,7 @@ class IdlUnionType(IdlTypeBase):
         return True
 
     def single_matching_member_type(self, predicate):
-        matching_types = filter(predicate, self.flattened_member_types)
+        matching_types = list(filter(predicate, self.flattened_member_types))
         if len(matching_types) > 1:
             raise ValueError('%s is ambiguous.' % self.name)
         return matching_types[0] if matching_types else None
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/utilities.py b/chromium/third_party/blink/renderer/bindings/scripts/utilities.py
index e1677ee7bd6..3c5006f064f 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/utilities.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/utilities.py
@@ -196,8 +196,9 @@ class ComponentInfoProviderModules(ComponentInfoProvider):
 
     @property
     def callback_functions(self):
-        return dict(self._component_info_core['callback_functions'].items() +
-                    self._component_info_modules['callback_functions'].items())
+        return dict(
+            list(self._component_info_core['callback_functions'].items()) +
+            list(self._component_info_modules['callback_functions'].items()))
 
     @property
     def specifier_for_export(self):
@@ -209,8 +210,8 @@ class ComponentInfoProviderModules(ComponentInfoProvider):
 
 
 def load_interfaces_info_overall_pickle(info_dir):
-    with open(os.path.join(info_dir,
-                           'interfaces_info.pickle')) as interface_info_file:
+    with open(os.path.join(info_dir, 'interfaces_info.pickle'),
+              mode='rb') as interface_info_file:
         return pickle.load(interface_info_file)
 
 
@@ -236,23 +237,20 @@ def merge_dict_recursively(target, diff):
 
 def create_component_info_provider_core(info_dir):
     interfaces_info = load_interfaces_info_overall_pickle(info_dir)
-    with open(
-            os.path.join(info_dir, 'core',
-                         'component_info_core.pickle')) as component_info_file:
+    with open(os.path.join(info_dir, 'core', 'component_info_core.pickle'),
+              mode='rb') as component_info_file:
         component_info = pickle.load(component_info_file)
     return ComponentInfoProviderCore(interfaces_info, component_info)
 
 
 def create_component_info_provider_modules(info_dir):
     interfaces_info = load_interfaces_info_overall_pickle(info_dir)
-    with open(
-            os.path.join(info_dir, 'core',
-                         'component_info_core.pickle')) as component_info_file:
+    with open(os.path.join(info_dir, 'core', 'component_info_core.pickle'),
+              mode='rb') as component_info_file:
         component_info_core = pickle.load(component_info_file)
-    with open(
-            os.path.join(
-                info_dir, 'modules',
-                'component_info_modules.pickle')) as component_info_file:
+    with open(os.path.join(info_dir, 'modules',
+                           'component_info_modules.pickle'),
+              mode='rb') as component_info_file:
         component_info_modules = pickle.load(component_info_file)
     return ComponentInfoProviderModules(interfaces_info, component_info_core,
                                         component_info_modules)
@@ -356,7 +354,7 @@ def write_pickle_file(pickle_filename, data):
     pickle_filename = abs(pickle_filename)
     # If |data| is same with the file content, we skip updating.
     if os.path.isfile(pickle_filename):
-        with open(pickle_filename) as pickle_file:
+        with open(pickle_filename, 'rb') as pickle_file:
             try:
                 if pickle.load(pickle_file) == data:
                     return
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/v8_interface.py b/chromium/third_party/blink/renderer/bindings/scripts/v8_interface.py
index a43260414db..a85b03abe75 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/v8_interface.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/v8_interface.py
@@ -189,7 +189,7 @@ def context_enabled_features(attributes):
         return sorted([
             member for member in members
             if member.get(KEY) and not member.get('exposed_test')
-        ])
+        ], key=lambda item: item['name'])
 
     def member_filter_by_name(members, name):
         return [member for member in members if member[KEY] == name]
@@ -612,7 +612,8 @@ def interface_context(interface, interfaces, component_info):
         sorted(
             origin_trial_features(interface, context['constants'],
                                   context['attributes'], context['methods']) +
-            context_enabled_features(context['attributes'])),
+            context_enabled_features(context['attributes']),
+            key=lambda item: item['name']),
     })
     if context['optional_features']:
         includes.add('platform/bindings/v8_per_context_data.h')
@@ -1356,9 +1357,9 @@ def resolution_tests_methods(effective_overloads):
 
     # Extract argument and IDL type to simplify accessing these in each loop.
     arguments = [method['arguments'][index] for method in methods]
-    arguments_methods = zip(arguments, methods)
+    arguments_methods = list(zip(arguments, methods))
     idl_types = [argument['idl_type_object'] for argument in arguments]
-    idl_types_methods = zip(idl_types, methods)
+    idl_types_methods = list(zip(idl_types, methods))
 
     # We can’t do a single loop through all methods or simply sort them, because
     # a method may be listed in multiple steps of the resolution algorithm, and
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/v8_methods.py b/chromium/third_party/blink/renderer/bindings/scripts/v8_methods.py
index 5f1f89a3def..6ee8a407798 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/v8_methods.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/v8_methods.py
@@ -46,6 +46,10 @@ import v8_types
 import v8_utilities
 from v8_utilities import (has_extended_attribute_value, is_unforgeable)
 
+# TODO: Remove this once Python2 is obsoleted.
+if sys.version_info.major != 2:
+    basestring = str
+
 
 def method_is_visible(method, interface_is_partial):
     if 'overloads' in method:
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/v8_utilities.py b/chromium/third_party/blink/renderer/bindings/scripts/v8_utilities.py
index 2ecd6923320..fcfc48371b1 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/v8_utilities.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/v8_utilities.py
@@ -271,7 +271,7 @@ EXPOSED_WORKERS = set([
 ])
 
 
-class ExposureSet:
+class ExposureSet(object):
     """An ExposureSet is a collection of Exposure instructions."""
 
     def __init__(self, exposures=None):
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/callback_interface.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/callback_interface.py
index 13fb7c7068d..b73b7710687 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/callback_interface.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/callback_interface.py
@@ -91,11 +91,13 @@ class CallbackInterface(UserDefinedType, WithExtendedAttributes,
             for operation_ir in ir.operations
         ])
         self._operation_groups = tuple([
-            OperationGroup(
-                operation_group_ir,
-                filter(lambda x: x.identifier == operation_group_ir.identifier,
-                       self._operations),
-                owner=self) for operation_group_ir in ir.operation_groups
+            OperationGroup(operation_group_ir,
+                           list(
+                               filter(
+                                   lambda x: x.identifier == operation_group_ir
+                                   .identifier, self._operations)),
+                           owner=self)
+            for operation_group_ir in ir.operation_groups
         ])
 
     @property
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/database.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/database.py
index c92cf48eb2a..f5d59129449 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/database.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/database.py
@@ -156,4 +156,4 @@ class Database(object):
         return self._view_by_kind(Database._Kind.UNION)
 
     def _view_by_kind(self, kind):
-        return self._impl.find_by_kind(kind).values()
+        return list(self._impl.find_by_kind(kind).values())
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/exposure.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/exposure.py
index abaeef39c30..e36cf7439ae 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/exposure.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/exposure.py
@@ -8,8 +8,11 @@ from .runtime_enabled_features import RuntimeEnabledFeatures
 class _Feature(str):
     """Represents a runtime-enabled feature."""
 
+    def __new__(cls, value):
+        return str.__new__(cls, value)
+
     def __init__(self, value):
-        str.__init__(self, value)
+        str.__init__(self)
         self._is_context_dependent = (
             RuntimeEnabledFeatures.is_context_dependent(self))
 
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/function_like.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/function_like.py
index 648c70d803d..1712f19c672 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/function_like.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/function_like.py
@@ -71,8 +71,9 @@ class FunctionLike(WithIdentifier):
     def num_of_required_arguments(self):
         """Returns the number of required arguments."""
         return len(
-            filter(lambda arg: not (arg.is_optional or arg.is_variadic),
-                   self.arguments))
+            list(
+                filter(lambda arg: not (arg.is_optional or arg.is_variadic),
+                       self.arguments)))
 
 
 class OverloadGroup(WithIdentifier):
@@ -171,8 +172,7 @@ class OverloadGroup(WithIdentifier):
         Returns the effective overload set.
         https://heycam.github.io/webidl/#compute-the-effective-overload-set
         """
-        assert argument_count is None or isinstance(argument_count,
-                                                    (int, long))
+        assert argument_count is None or isinstance(argument_count, int)
 
         N = argument_count
         S = []
@@ -188,21 +188,21 @@ class OverloadGroup(WithIdentifier):
 
             S.append(
                 OverloadGroup.EffectiveOverloadItem(
-                    X, map(lambda arg: arg.idl_type, X.arguments),
-                    map(lambda arg: arg.optionality, X.arguments)))
+                    X, list(map(lambda arg: arg.idl_type, X.arguments)),
+                    list(map(lambda arg: arg.optionality, X.arguments))))
 
             if X.is_variadic:
-                for i in xrange(n, max(maxarg, N)):
-                    t = map(lambda arg: arg.idl_type, X.arguments)
-                    o = map(lambda arg: arg.optionality, X.arguments)
-                    for _ in xrange(n, i + 1):
+                for i in range(n, max(maxarg, N)):
+                    t = list(map(lambda arg: arg.idl_type, X.arguments))
+                    o = list(map(lambda arg: arg.optionality, X.arguments))
+                    for _ in range(n, i + 1):
                         t.append(X.arguments[-1].idl_type)
                         o.append(X.arguments[-1].optionality)
                     S.append(OverloadGroup.EffectiveOverloadItem(X, t, o))
 
-            t = map(lambda arg: arg.idl_type, X.arguments)
-            o = map(lambda arg: arg.optionality, X.arguments)
-            for i in xrange(n - 1, -1, -1):
+            t = list(map(lambda arg: arg.idl_type, X.arguments))
+            o = list(map(lambda arg: arg.optionality, X.arguments))
+            for i in range(n - 1, -1, -1):
                 if X.arguments[i].optionality == IdlType.Optionality.REQUIRED:
                     break
                 S.append(OverloadGroup.EffectiveOverloadItem(X, t[:i], o[:i]))
@@ -222,7 +222,7 @@ class OverloadGroup(WithIdentifier):
             for item in items)
         assert len(items) > 1
 
-        for index in xrange(len(items[0].type_list)):
+        for index in range(len(items[0].type_list)):
             # Assume that the given items are valid, and we only need to test
             # the two types.
             if OverloadGroup.are_distinguishable_types(
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/idl_compiler.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/idl_compiler.py
index c5ee2bd8a3d..58315072480 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/idl_compiler.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/idl_compiler.py
@@ -149,8 +149,8 @@ class IdlCompiler(object):
         for old_ir in old_irs:
             new_ir = make_copy(old_ir)
             self._ir_map.add(new_ir)
-            new_ir.attributes = filter(not_disabled, new_ir.attributes)
-            new_ir.operations = filter(not_disabled, new_ir.operations)
+            new_ir.attributes = list(filter(not_disabled, new_ir.attributes))
+            new_ir.operations = list(filter(not_disabled, new_ir.operations))
 
     def _record_defined_in_partial_and_mixin(self):
         old_irs = self._ir_map.irs_of_kinds(
@@ -231,7 +231,7 @@ class IdlCompiler(object):
                       only_to_members_of_partial_or_mixin=False)
             propagate_to_exposure(propagate)
 
-            map(process_member_like, ir.iter_all_members())
+            list(map(process_member_like, ir.iter_all_members()))
 
         def process_member_like(ir):
             propagate = functools.partial(propagate_extattr, ir=ir)
@@ -257,7 +257,7 @@ class IdlCompiler(object):
 
         self._ir_map.move_to_new_phase()
 
-        map(process_interface_like, old_irs)
+        list(map(process_interface_like, old_irs))
 
     def _determine_blink_headers(self):
         irs = self._ir_map.irs_of_kinds(
@@ -422,9 +422,9 @@ class IdlCompiler(object):
             assert not new_interface.deriveds
             derived_set = identifier_to_derived_set.get(
                 new_interface.identifier, set())
-            new_interface.deriveds = map(
-                lambda id_: self._ref_to_idl_def_factory.create(id_),
-                sorted(derived_set))
+            new_interface.deriveds = list(
+                map(lambda id_: self._ref_to_idl_def_factory.create(id_),
+                    sorted(derived_set)))
 
     def _supplement_missing_html_constructor_operation(self):
         # Temporary mitigation of misuse of [HTMLConstructor]
@@ -553,7 +553,8 @@ class IdlCompiler(object):
             self._ir_map.add(new_ir)
 
             for group in new_ir.iter_all_overload_groups():
-                exposures = map(lambda overload: overload.exposure, group)
+                exposures = list(map(lambda overload: overload.exposure,
+                                     group))
 
                 # [Exposed]
                 if any(not exposure.global_names_and_features
@@ -653,8 +654,8 @@ class IdlCompiler(object):
             constructs = set()
             for global_name in global_names:
                 constructs.update(exposed_map.get(global_name, []))
-            new_ir.exposed_constructs = map(
-                self._ref_to_idl_def_factory.create, sorted(constructs))
+            new_ir.exposed_constructs = list(
+                map(self._ref_to_idl_def_factory.create, sorted(constructs)))
 
             assert not new_ir.legacy_window_aliases
             if new_ir.identifier != 'Window':
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/interface.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/interface.py
index 65d24e529d1..067ef2eb0b2 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/interface.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/interface.py
@@ -180,8 +180,9 @@ class Interface(UserDefinedType, WithExtendedAttributes, WithCodeGeneratorInfo,
         self._constructor_groups = tuple([
             ConstructorGroup(
                 group_ir,
-                filter(lambda x: x.identifier == group_ir.identifier,
-                       self._constructors),
+                list(
+                    filter(lambda x: x.identifier == group_ir.identifier,
+                           self._constructors)),
                 owner=self) for group_ir in ir.constructor_groups
         ])
         assert len(self._constructor_groups) <= 1
@@ -192,8 +193,9 @@ class Interface(UserDefinedType, WithExtendedAttributes, WithCodeGeneratorInfo,
         self._named_constructor_groups = tuple([
             ConstructorGroup(
                 group_ir,
-                filter(lambda x: x.identifier == group_ir.identifier,
-                       self._named_constructors),
+                list(
+                    filter(lambda x: x.identifier == group_ir.identifier,
+                           self._named_constructors)),
                 owner=self) for group_ir in ir.named_constructor_groups
         ])
         self._operations = tuple([
@@ -203,22 +205,23 @@ class Interface(UserDefinedType, WithExtendedAttributes, WithCodeGeneratorInfo,
         self._operation_groups = tuple([
             OperationGroup(
                 group_ir,
-                filter(lambda x: x.identifier == group_ir.identifier,
-                       self._operations),
+                list(
+                    filter(lambda x: x.identifier == group_ir.identifier,
+                           self._operations)),
                 owner=self) for group_ir in ir.operation_groups
         ])
         self._exposed_constructs = tuple(ir.exposed_constructs)
         self._legacy_window_aliases = tuple(ir.legacy_window_aliases)
         self._indexed_and_named_properties = None
-        indexed_and_named_property_operations = filter(
-            lambda x: x.is_indexed_or_named_property_operation,
-            self._operations)
+        indexed_and_named_property_operations = list(
+            filter(lambda x: x.is_indexed_or_named_property_operation,
+                   self._operations))
         if indexed_and_named_property_operations:
             self._indexed_and_named_properties = IndexedAndNamedProperties(
                 indexed_and_named_property_operations, owner=self)
         self._stringifier = None
-        stringifier_operation_irs = filter(lambda x: x.is_stringifier,
-                                           ir.operations)
+        stringifier_operation_irs = list(
+            filter(lambda x: x.is_stringifier, ir.operations))
         if stringifier_operation_irs:
             assert len(stringifier_operation_irs) == 1
             op_ir = make_copy(stringifier_operation_irs[0])
@@ -231,8 +234,9 @@ class Interface(UserDefinedType, WithExtendedAttributes, WithCodeGeneratorInfo,
             attribute = None
             if operation.stringifier_attribute:
                 attr_id = operation.stringifier_attribute
-                attributes = filter(lambda x: x.identifier == attr_id,
-                                    self._attributes)
+                attributes = list(
+                    filter(lambda x: x.identifier == attr_id,
+                           self._attributes))
                 assert len(attributes) == 1
                 attribute = attributes[0]
             self._stringifier = Stringifier(operation, attribute, owner=self)
@@ -578,8 +582,9 @@ class Iterable(WithDebugInfo):
         self._operation_groups = tuple([
             OperationGroup(
                 group_ir,
-                filter(lambda x: x.identifier == group_ir.identifier,
-                       self._operations),
+                list(
+                    filter(lambda x: x.identifier == group_ir.identifier,
+                           self._operations)),
                 owner=owner) for group_ir in ir.operation_groups
         ])
 
@@ -666,8 +671,9 @@ class Maplike(WithDebugInfo):
         self._operation_groups = tuple([
             OperationGroup(
                 group_ir,
-                filter(lambda x: x.identifier == group_ir.identifier,
-                       self._operations),
+                list(
+                    filter(lambda x: x.identifier == group_ir.identifier,
+                           self._operations)),
                 owner=owner) for group_ir in ir.operation_groups
         ])
 
@@ -755,8 +761,9 @@ class Setlike(WithDebugInfo):
         self._operation_groups = tuple([
             OperationGroup(
                 group_ir,
-                filter(lambda x: x.identifier == group_ir.identifier,
-                       self._operations),
+                list(
+                    filter(lambda x: x.identifier == group_ir.identifier,
+                           self._operations)),
                 owner=owner) for group_ir in ir.operation_groups
         ])
 
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/ir_builder.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/ir_builder.py
index e9aeff4ab82..d80554d603e 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/ir_builder.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/ir_builder.py
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import sys
+
 from .argument import Argument
 from .ast_group import AstGroup
 from .attribute import Attribute
@@ -30,6 +32,11 @@ from .operation import Operation
 from .typedef import Typedef
 
 
+# TODO: Remove this once Python2 is obsoleted.
+if sys.version_info.major != 2:
+    long = int
+
+
 def load_and_register_idl_definitions(filepaths, register_ir,
                                       create_ref_to_idl_def, idl_type_factory):
     """
@@ -160,7 +167,7 @@ class _IRBuilder(object):
         child_nodes = list(node.GetChildren())
         extended_attributes = self._take_extended_attributes(child_nodes)
 
-        members = map(self._build_interface_member, child_nodes)
+        members = list(map(self._build_interface_member, child_nodes))
         attributes = []
         constants = []
         operations = []
@@ -302,7 +309,7 @@ class _IRBuilder(object):
         child_nodes = list(node.GetChildren())
         inherited = self._take_inheritance(child_nodes)
         extended_attributes = self._take_extended_attributes(child_nodes)
-        own_members = map(self._build_dictionary_member, child_nodes)
+        own_members = list(map(self._build_dictionary_member, child_nodes))
 
         return Dictionary.IR(
             identifier=Identifier(node.GetName()),
@@ -336,7 +343,7 @@ class _IRBuilder(object):
 
         child_nodes = list(node.GetChildren())
         extended_attributes = self._take_extended_attributes(child_nodes)
-        members = map(self._build_interface_member, child_nodes)
+        members = list(map(self._build_interface_member, child_nodes))
         constants = []
         operations = []
         for member in members:
@@ -456,8 +463,8 @@ class _IRBuilder(object):
                 assert len(child_nodes) == 1
                 child = child_nodes[0]
                 if child.GetClass() == 'Arguments':
-                    arguments = map(build_extattr_argument,
-                                    child.GetChildren())
+                    arguments = list(
+                        map(build_extattr_argument, child.GetChildren()))
                 elif child.GetClass() == 'Call':
                     assert len(child.GetChildren()) == 1
                     grand_child = child.GetChildren()[0]
@@ -486,7 +493,9 @@ class _IRBuilder(object):
 
         assert node.GetClass() == 'ExtAttributes'
         return ExtendedAttributes(
-            filter(None, map(build_extended_attribute, node.GetChildren())))
+            list(
+                filter(None, map(build_extended_attribute,
+                                 node.GetChildren()))))
 
     def _build_inheritance(self, node):
         assert node.GetClass() == 'Inherit'
@@ -506,7 +515,7 @@ class _IRBuilder(object):
 
     def _build_iterable(self, node):
         assert node.GetClass() == 'Iterable'
-        types = map(self._build_type, node.GetChildren())
+        types = list(map(self._build_type, node.GetChildren()))
         assert len(types) == 1 or len(types) == 2
         if len(types) == 1:  # value iterator
             key_type, value_type = (None, types[0])
@@ -584,7 +593,7 @@ class _IRBuilder(object):
     def _build_maplike(self, node, interface_identifier):
         assert node.GetClass() == 'Maplike'
         assert isinstance(interface_identifier, Identifier)
-        types = map(self._build_type, node.GetChildren())
+        types = list(map(self._build_type, node.GetChildren()))
         assert len(types) == 2
         key_type, value_type = types
         is_readonly = bool(node.GetProperty('READONLY'))
@@ -676,7 +685,7 @@ class _IRBuilder(object):
     def _build_setlike(self, node, interface_identifier):
         assert node.GetClass() == 'Setlike'
         assert isinstance(interface_identifier, Identifier)
-        types = map(self._build_type, node.GetChildren())
+        types = list(map(self._build_type, node.GetChildren()))
         assert len(types) == 1
         value_type = types[0]
         is_readonly = bool(node.GetProperty('READONLY'))
@@ -838,7 +847,7 @@ class _IRBuilder(object):
 
         def build_union_type(node, extended_attributes):
             return self._idl_type_factory.union_type(
-                member_types=map(self._build_type, node.GetChildren()),
+                member_types=list(map(self._build_type, node.GetChildren())),
                 is_optional=is_optional,
                 extended_attributes=extended_attributes,
                 debug_info=self._build_debug_info(node))
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/make_copy.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/make_copy.py
index a7a2b11f3f0..2f6b61300ff 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/make_copy.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/make_copy.py
@@ -3,6 +3,13 @@
 # found in the LICENSE file.
 
 
+import sys
+
+# TODO: Remove this once Python2 is obsoleted.
+if sys.version_info.major != 2:
+    long = int
+    basestring = str
+
 def make_copy(obj, memo=None):
     """
     Creates a copy of the given object, which should be an IR or part of IR.
diff --git a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/namespace.py b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/namespace.py
index eeabef97cbe..bd7e98907f3 100644
--- a/chromium/third_party/blink/renderer/bindings/scripts/web_idl/namespace.py
+++ b/chromium/third_party/blink/renderer/bindings/scripts/web_idl/namespace.py
@@ -107,11 +107,13 @@ class Namespace(UserDefinedType, WithExtendedAttributes, WithCodeGeneratorInfo,
             for operation_ir in ir.operations
         ])
         self._operation_groups = tuple([
-            OperationGroup(
-                operation_group_ir,
-                filter(lambda x: x.identifier == operation_group_ir.identifier,
-                       self._operations),
-                owner=self) for operation_group_ir in ir.operation_groups
+            OperationGroup(operation_group_ir,
+                           list(
+                               filter(
+                                   lambda x: x.identifier == operation_group_ir
+                                   .identifier, self._operations)),
+                           owner=self)
+            for operation_group_ir in ir.operation_groups
         ])
 
     @property
diff --git a/chromium/third_party/blink/renderer/bindings/templates/dictionary_v8.cc.tmpl b/chromium/third_party/blink/renderer/bindings/templates/dictionary_v8.cc.tmpl
index 0add9c45a38..dc910f6d227 100644
--- a/chromium/third_party/blink/renderer/bindings/templates/dictionary_v8.cc.tmpl
+++ b/chromium/third_party/blink/renderer/bindings/templates/dictionary_v8.cc.tmpl
@@ -59,9 +59,9 @@ void {{v8_class}}::ToImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8_value, {
   DCHECK(executionContext);
   {% endif %}{# has_origin_trial_members #}
   {% endif %}{# members #}
-  {% for origin_trial_test, origin_trial_member_list in members | groupby('origin_trial_feature_name') %}
+  {% for origin_trial_test, origin_trial_member_list in members | stringifykeygroupby('origin_trial_feature_name') %}
   {% filter origin_trial_enabled(origin_trial_test, "executionContext") %}
-  {% for feature_name, member_list in origin_trial_member_list | groupby('runtime_enabled_feature_name') %}
+  {% for feature_name, member_list in origin_trial_member_list | stringifykeygroupby('runtime_enabled_feature_name') %}
   {% filter runtime_enabled(feature_name) %}
   {% for member in member_list %}
   v8::Local<v8::Value> {{member.v8_value}};
@@ -147,9 +147,9 @@ bool toV8{{cpp_class}}(const {{cpp_class}}* impl, v8::Local<v8::Object> dictiona
   DCHECK(executionContext);
   {% endif %}{# has_origin_trial_members #}
   {% endif %}{# members #}
-  {% for origin_trial_test, origin_trial_member_list in members | groupby('origin_trial_feature_name') %}
+  {% for origin_trial_test, origin_trial_member_list in members | stringifykeygroupby('origin_trial_feature_name') %}
   {% filter origin_trial_enabled(origin_trial_test, "executionContext") %}
-  {% for feature_name, member_list in origin_trial_member_list | groupby('runtime_enabled_feature_name') %}
+  {% for feature_name, member_list in origin_trial_member_list | stringifykeygroupby('runtime_enabled_feature_name') %}
   {% filter runtime_enabled(feature_name) %}
   {% for member in member_list %}
   v8::Local<v8::Value> {{member.v8_value}};
diff --git a/chromium/third_party/blink/renderer/build/scripts/core/css/make_style_shorthands.py b/chromium/third_party/blink/renderer/build/scripts/core/css/make_style_shorthands.py
index 1799cd5a153..5f43ffabc26 100755
--- a/chromium/third_party/blink/renderer/build/scripts/core/css/make_style_shorthands.py
+++ b/chromium/third_party/blink/renderer/build/scripts/core/css/make_style_shorthands.py
@@ -71,7 +71,7 @@ class Expansion(object):
     def enabled_longhands(self):
         include = lambda longhand: not longhand[
             'runtime_flag'] or self.is_enabled(longhand['runtime_flag'])
-        return filter(include, self._longhands)
+        return list(filter(include, self._longhands))
 
     @property
     def index(self):
@@ -87,8 +87,9 @@ class Expansion(object):
 
 def create_expansions(longhands):
     flags = collect_runtime_flags(longhands)
-    expansions = map(lambda mask: Expansion(longhands, flags, mask),
-                     range(1 << len(flags)))
+    expansions = list(
+        map(lambda mask: Expansion(longhands, flags, mask),
+            range(1 << len(flags))))
     assert len(expansions) > 0
     # We generate 2^N expansions for N flags, so enforce some limit.
     assert len(flags) <= 4, 'Too many runtime flags for a single shorthand'
@@ -114,14 +115,14 @@ class StylePropertyShorthandWriter(json5_generator.Writer):
 
         self._longhand_dictionary = defaultdict(list)
         for property_ in json5_properties.shorthands:
-            property_['longhand_enum_keys'] = map(enum_key_for_css_property,
-                                                  property_['longhands'])
-            property_['longhand_property_ids'] = map(id_for_css_property,
-                                                     property_['longhands'])
-
-            longhands = map(
-                lambda name: json5_properties.properties_by_name[name],
-                property_['longhands'])
+            property_['longhand_enum_keys'] = list(
+                map(enum_key_for_css_property, property_['longhands']))
+            property_['longhand_property_ids'] = list(
+                map(id_for_css_property, property_['longhands']))
+
+            longhands = list(
+                map(lambda name: json5_properties.properties_by_name[name],
+                    property_['longhands']))
             property_['expansions'] = create_expansions(longhands)
             for longhand_enum_key in property_['longhand_enum_keys']:
                 self._longhand_dictionary[longhand_enum_key].append(property_)
diff --git a/chromium/third_party/blink/renderer/build/scripts/core/css/properties/make_css_property_instances.py b/chromium/third_party/blink/renderer/build/scripts/core/css/properties/make_css_property_instances.py
index 75030ac577e..f72aadee17d 100755
--- a/chromium/third_party/blink/renderer/build/scripts/core/css/properties/make_css_property_instances.py
+++ b/chromium/third_party/blink/renderer/build/scripts/core/css/properties/make_css_property_instances.py
@@ -42,8 +42,8 @@ class CSSPropertyInstancesWriter(json5_generator.Writer):
         aliases = self._css_properties.aliases
 
         # Lists of PropertyClassData.
-        self._property_classes_by_id = map(self.get_class, properties)
-        self._alias_classes_by_id = map(self.get_class, aliases)
+        self._property_classes_by_id = list(map(self.get_class, properties))
+        self._alias_classes_by_id = list(map(self.get_class, aliases))
 
         # Sort by enum value.
         self._property_classes_by_id.sort(key=lambda t: t.enum_value)
diff --git a/chromium/third_party/blink/renderer/build/scripts/gperf.py b/chromium/third_party/blink/renderer/build/scripts/gperf.py
index 5ee49056be4..db72660d471 100644
--- a/chromium/third_party/blink/renderer/build/scripts/gperf.py
+++ b/chromium/third_party/blink/renderer/build/scripts/gperf.py
@@ -95,7 +95,7 @@ def main():
 
     open(args.output_file, 'wb').write(
         generate_gperf(gperf_path,
-                       open(infile).read(), gperf_args))
+                       open(infile).read(), gperf_args).encode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/chromium/third_party/blink/renderer/build/scripts/in_file.py b/chromium/third_party/blink/renderer/build/scripts/in_file.py
index 28adc050f1e..58113483e57 100644
--- a/chromium/third_party/blink/renderer/build/scripts/in_file.py
+++ b/chromium/third_party/blink/renderer/build/scripts/in_file.py
@@ -66,7 +66,7 @@ class InFile(object):
         self._defaults = defaults
         self._valid_values = copy.deepcopy(
             valid_values if valid_values else {})
-        self._parse(map(str.strip, lines))
+        self._parse(list(map(str.strip, lines)))
 
     @classmethod
     def load_from_files(self, file_paths, defaults, valid_values,
diff --git a/chromium/third_party/blink/renderer/build/scripts/in_generator.py b/chromium/third_party/blink/renderer/build/scripts/in_generator.py
index e46740a2e85..ab1981ad1e3 100644
--- a/chromium/third_party/blink/renderer/build/scripts/in_generator.py
+++ b/chromium/third_party/blink/renderer/build/scripts/in_generator.py
@@ -32,10 +32,15 @@ import os
 import os.path
 import shlex
 import shutil
+import sys
 import optparse
 
 from in_file import InFile
 
+# TODO: Remove this once Python2 is obsoleted.
+if sys.version_info.major != 2:
+    basestring = str
+
 
 #########################################################
 # This is now deprecated - use json5_generator.py instead
diff --git a/chromium/third_party/blink/renderer/build/scripts/make_runtime_features.py b/chromium/third_party/blink/renderer/build/scripts/make_runtime_features.py
index cafe8d94a8e..6925a4fa580 100755
--- a/chromium/third_party/blink/renderer/build/scripts/make_runtime_features.py
+++ b/chromium/third_party/blink/renderer/build/scripts/make_runtime_features.py
@@ -138,7 +138,7 @@ class RuntimeFeatureWriter(BaseRuntimeFeatureWriter):
                 except Exception:
                     # If trouble unpickling, overwrite
                     pass
-        with open(os.path.abspath(file_name), 'w') as pickle_file:
+        with open(os.path.abspath(file_name), 'wb') as pickle_file:
             pickle.dump(features_map, pickle_file)
 
     def _template_inputs(self):
diff --git a/chromium/third_party/blink/renderer/build/scripts/templates/element_factory.cc.tmpl b/chromium/third_party/blink/renderer/build/scripts/templates/element_factory.cc.tmpl
index dc3f44c5b10..3eefcf9f0ee 100644
--- a/chromium/third_party/blink/renderer/build/scripts/templates/element_factory.cc.tmpl
+++ b/chromium/third_party/blink/renderer/build/scripts/templates/element_factory.cc.tmpl
@@ -26,7 +26,7 @@ using {{namespace}}FunctionMap = HashMap<AtomicString, {{namespace}}ConstructorF
 
 static {{namespace}}FunctionMap* g_{{namespace|lower}}_constructors = nullptr;
 
-{% for tag in tags|sort if not tag.noConstructor %}
+{% for tag in tags|sort(attribute='name') if not tag.noConstructor %}
 static {{namespace}}Element* {{namespace}}{{tag.name.to_upper_camel_case()}}Constructor(
     Document& document, const CreateElementFlags flags) {
   {% if tag.runtimeEnabled %}
@@ -52,7 +52,7 @@ static void Create{{namespace}}FunctionMap() {
   // Empty array initializer lists are illegal [dcl.init.aggr] and will not
   // compile in MSVC. If tags list is empty, add check to skip this.
   static const Create{{namespace}}FunctionMapData data[] = {
-  {% for tag in tags|sort if not tag.noConstructor %}
+  {% for tag in tags|sort(attribute='name') if not tag.noConstructor %}
     { {{cpp_namespace}}::{{tag|symbol}}Tag, {{namespace}}{{tag.name.to_upper_camel_case()}}Constructor },
   {% endfor %}
   };
diff --git a/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.cc.tmpl b/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.cc.tmpl
index 9bfc489e048..5f86184e879 100644
--- a/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.cc.tmpl
+++ b/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.cc.tmpl
@@ -22,7 +22,7 @@ HTMLTypeMap CreateHTMLTypeMap() {
     const char* name;
     HTMLElementType type;
   } kTags[] = {
-    {% for tag in tags|sort %}
+    {% for tag in tags|sort(attribute='name') %}
     { "{{tag.name}}", HTMLElementType::k{{tag.js_interface}} },
     {% endfor %}
   };
@@ -42,7 +42,7 @@ HTMLElementType htmlElementTypeForTag(const AtomicString& tagName, const Documen
   if (it == html_type_map.end())
     return HTMLElementType::kHTMLUnknownElement;
 
-  {% for tag in tags|sort %}
+  {% for tag in tags|sort(attribute='name') %}
   {% if tag.runtimeEnabled %}
   if (tagName == "{{tag.name}}") {
     if (!RuntimeEnabledFeatures::{{tag.runtimeEnabled}}Enabled(document->GetExecutionContext())) {
diff --git a/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.h.tmpl b/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.h.tmpl
index 1b5297d52dc..edecc81d9d4 100644
--- a/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.h.tmpl
+++ b/chromium/third_party/blink/renderer/build/scripts/templates/element_type_helpers.h.tmpl
@@ -15,7 +15,7 @@ namespace blink {
 class Document;
 
 // Type checking.
-{% for tag in tags|sort if not tag.multipleTagNames and not tag.noTypeHelpers %}
+{% for tag in tags|sort(attribute='name') if not tag.multipleTagNames and not tag.noTypeHelpers %}
 class {{tag.interface}};
 template <>
 inline bool IsElementOfType<const {{tag.interface}}>(const Node& node) {
diff --git a/chromium/third_party/blink/renderer/build/scripts/templates/macros.tmpl b/chromium/third_party/blink/renderer/build/scripts/templates/macros.tmpl
index 0244433af2e..dcdbb02a56c 100644
--- a/chromium/third_party/blink/renderer/build/scripts/templates/macros.tmpl
+++ b/chromium/third_party/blink/renderer/build/scripts/templates/macros.tmpl
@@ -25,7 +25,7 @@
 
 
 {% macro trie_leaf(index, object, return_macro, lowercase_data) %}
-{% set name, value = object.items()[0] %}
+{% set name, value = (object.items()|list)[0] %}
 {% if name|length %}
 if (
     {%- for c in name -%}
@@ -45,7 +45,7 @@ return {{ return_macro(value) }};
 
 
 {% macro trie_switch(trie, index, return_macro, lowercase_data) %}
-{% if trie|length == 1 and trie.values()[0] is string %}
+{% if trie|length == 1 and (trie.values()|list)[0] is string %}
 {{ trie_leaf(index, trie, return_macro, lowercase_data) -}}
 {% else %}
     {% if lowercase_data %}
diff --git a/chromium/third_party/blink/renderer/build/scripts/templates/make_qualified_names.h.tmpl b/chromium/third_party/blink/renderer/build/scripts/templates/make_qualified_names.h.tmpl
index cb05c6c4315..bd5566b03e7 100644
--- a/chromium/third_party/blink/renderer/build/scripts/templates/make_qualified_names.h.tmpl
+++ b/chromium/third_party/blink/renderer/build/scripts/templates/make_qualified_names.h.tmpl
@@ -24,12 +24,12 @@ namespace {{cpp_namespace}} {
 {{symbol_export}}extern const WTF::AtomicString& {{namespace_prefix}}NamespaceURI;
 
 // Tags
-{% for tag in tags|sort %}
+{% for tag in tags|sort(attribute='name') %}
 {{symbol_export}}extern const blink::{{namespace}}QualifiedName& {{tag|symbol}}Tag;
 {% endfor %}
 
 // Attributes
-{% for attr in attrs|sort %}
+{% for attr in attrs|sort(attribute='name') %}
 {{symbol_export}}extern const blink::QualifiedName& {{attr|symbol}}Attr;
 {% endfor %}
 
diff --git a/chromium/third_party/devtools-frontend/src/BUILD.gn b/chromium/third_party/devtools-frontend/src/BUILD.gn
index cd488e88b60..ea1dc3d9a79 100644
--- a/chromium/third_party/devtools-frontend/src/BUILD.gn
+++ b/chromium/third_party/devtools-frontend/src/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/python.gni")
+
 import("//third_party/blink/public/public_features.gni")
 import("./all_devtools_files.gni")
 import("./all_devtools_modules.gni")
diff --git a/chromium/third_party/devtools-frontend/src/scripts/build/build_inspector_overlay.py b/chromium/third_party/devtools-frontend/src/scripts/build/build_inspector_overlay.py
index d6666e8b74f..0f7a661e632 100644
--- a/chromium/third_party/devtools-frontend/src/scripts/build/build_inspector_overlay.py
+++ b/chromium/third_party/devtools-frontend/src/scripts/build/build_inspector_overlay.py
@@ -45,7 +45,8 @@ def rollup(input_path, output_path, filename, max_size, rollup_plugin):
         ['--format', 'iife', '-n', 'InspectorOverlay'] + ['--input', target] +
         ['--plugin', rollup_plugin],
         stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE)
+        stderr=subprocess.PIPE,
+        text=True)
     out, error = rollup_process.communicate()
     if not out:
         raise Exception("rollup failed: " + error)
diff --git a/chromium/third_party/devtools-frontend/src/scripts/build/build_release_applications.py b/chromium/third_party/devtools-frontend/src/scripts/build/build_release_applications.py
index fa8e73d34af..7d0b84b2171 100644
--- a/chromium/third_party/devtools-frontend/src/scripts/build/build_release_applications.py
+++ b/chromium/third_party/devtools-frontend/src/scripts/build/build_release_applications.py
@@ -10,7 +10,7 @@ Builds applications in release mode:
 and the application loader into a single script.
 """
 
-from cStringIO import StringIO
+from io import StringIO
 from os import path
 from os.path import join
 import copy
@@ -145,8 +145,7 @@ class ReleaseBuilder(object):
             resource_content = read_file(path.join(self.application_dir, resource_name))
             if not (resource_name.endswith('.html')
                     or resource_name.endswith('md')):
-                resource_content += resource_source_url(resource_name).encode(
-                    'utf-8')
+                resource_content += resource_source_url(resource_name)
             resource_content = resource_content.replace('\\', '\\\\')
             resource_content = resource_content.replace('\n', '\\n')
             resource_content = resource_content.replace('"', '\\"')
@@ -173,7 +172,9 @@ class ReleaseBuilder(object):
     def _concatenate_application_script(self, output):
         output.write('Root.allDescriptors.push(...%s);' % self._release_module_descriptors())
         if self.descriptors.extends:
-            output.write('Root.applicationDescriptor.modules.push(...%s);' % json.dumps(self.descriptors.application.values()))
+            output.write(
+                'Root.applicationDescriptor.modules.push(...%s);' %
+                json.dumps(list(self.descriptors.application.values())))
         else:
             output.write('Root.applicationDescriptor = %s;' % self.descriptors.application_json())
 
diff --git a/chromium/third_party/devtools-frontend/src/scripts/build/generate_devtools_grd.py b/chromium/third_party/devtools-frontend/src/scripts/build/generate_devtools_grd.py
index be510c48d76..c6a59c90298 100644
--- a/chromium/third_party/devtools-frontend/src/scripts/build/generate_devtools_grd.py
+++ b/chromium/third_party/devtools-frontend/src/scripts/build/generate_devtools_grd.py
@@ -123,7 +123,7 @@ def main(argv):
 
     try:
         os.makedirs(path.join(output_directory, 'Images'))
-    except OSError, e:
+    except OSError as e:
         if e.errno != errno.EEXIST:
             raise e
 
@@ -147,7 +147,7 @@ def main(argv):
             shutil.copy(path.join(dirname, filename), path.join(output_directory, 'Images'))
             add_file_to_grd(doc, path.join('Images', filename))
 
-    with open(parsed_args.output_filename, 'w') as output_file:
+    with open(parsed_args.output_filename, 'wb') as output_file:
         output_file.write(doc.toxml(encoding='UTF-8'))
 
 
diff --git a/chromium/third_party/devtools-frontend/src/scripts/build/modular_build.py b/chromium/third_party/devtools-frontend/src/scripts/build/modular_build.py
index 0ba695d3810..bb1da2f9f8d 100644
--- a/chromium/third_party/devtools-frontend/src/scripts/build/modular_build.py
+++ b/chromium/third_party/devtools-frontend/src/scripts/build/modular_build.py
@@ -7,6 +7,8 @@
 Utilities for the modular DevTools build.
 """
 
+from __future__ import print_function
+
 import collections
 from os import path
 import os
@@ -40,7 +42,7 @@ def load_and_parse_json(filename):
     try:
         return json.loads(read_file(filename))
     except:
-        print 'ERROR: Failed to parse %s' % filename
+        print('ERROR: Failed to parse %s' % filename)
         raise
 
 class Descriptors:
@@ -57,7 +59,7 @@ class Descriptors:
 
     def application_json(self):
         result = dict()
-        result['modules'] = self.application.values()
+        result['modules'] = list(self.application.values())
         return json.dumps(result)
 
     def all_compiled_files(self):
diff --git a/chromium/tools/metrics/ukm/gen_builders.py b/chromium/tools/metrics/ukm/gen_builders.py
index f9f61d90a56..44e46fae8cc 100755
--- a/chromium/tools/metrics/ukm/gen_builders.py
+++ b/chromium/tools/metrics/ukm/gen_builders.py
@@ -48,9 +48,10 @@ def ReadFilteredData(path):
     data = ukm_model.UKM_XML_TYPE.Parse(ukm_file.read())
     event_tag = ukm_model._EVENT_TYPE.tag
     metric_tag = ukm_model._METRIC_TYPE.tag
-    data[event_tag] = filter(ukm_model.IsNotObsolete, data[event_tag])
+    data[event_tag] = list(filter(ukm_model.IsNotObsolete, data[event_tag]))
     for event in data[event_tag]:
-      event[metric_tag] = filter(ukm_model.IsNotObsolete, event[metric_tag])
+      event[metric_tag] = list(
+          filter(ukm_model.IsNotObsolete, event[metric_tag]))
     return data
 
 
diff --git a/chromium/ui/ozone/generate_constructor_list.py b/chromium/ui/ozone/generate_constructor_list.py
index 8d800636c97..04fa18e93df 100755
--- a/chromium/ui/ozone/generate_constructor_list.py
+++ b/chromium/ui/ozone/generate_constructor_list.py
@@ -45,12 +45,15 @@ Example Output: ./ui/ozone/generate_constructor_list.py \
   }  // namespace ui
 """
 
+try:
+    from StringIO import StringIO  # for Python 2
+except ImportError:
+    from io import StringIO  # for Python 3
 import optparse
 import os
 import collections
 import re
 import sys
-import string
 
 
 def GetTypedefName(typename):
@@ -68,7 +71,7 @@ def GetConstructorName(typename, platform):
   This is just "Create" + typename + platform.
   """
 
-  return 'Create' + typename + string.capitalize(platform)
+  return 'Create' + typename + platform.capitalize()
 
 
 def GenerateConstructorList(out, namespace, export, typenames, platforms,
@@ -163,12 +166,14 @@ def main(argv):
     sys.exit(1)
 
   # Write to standard output or file specified by --output_cc.
-  out_cc = sys.stdout
+  out_cc = getattr(sys.stdout, 'buffer', sys.stdout)
   if options.output_cc:
     out_cc = open(options.output_cc, 'wb')
 
-  GenerateConstructorList(out_cc, options.namespace, options.export,
+  out_cc_str = StringIO()
+  GenerateConstructorList(out_cc_str, options.namespace, options.export,
                           typenames, platforms, includes, usings)
+  out_cc.write(out_cc_str.getvalue().encode('utf-8'))
 
   if options.output_cc:
     out_cc.close()
diff --git a/chromium/ui/ozone/generate_ozone_platform_list.py b/chromium/ui/ozone/generate_ozone_platform_list.py
index d47c398259b..2702b68b9bd 100755
--- a/chromium/ui/ozone/generate_ozone_platform_list.py
+++ b/chromium/ui/ozone/generate_ozone_platform_list.py
@@ -49,12 +49,15 @@ Example Output: ./generate_ozone_platform_list.py --default wayland dri wayland
 
 """
 
+try:
+    from StringIO import StringIO  # for Python 2
+except ImportError:
+    from io import StringIO  # for Python 3
 import optparse
 import os
 import collections
 import re
 import sys
-import string
 
 
 def GetConstantName(name):
@@ -63,7 +66,7 @@ def GetConstantName(name):
   We just capitalize the platform name and prepend "CreateOzonePlatform".
   """
 
-  return 'kPlatform' + string.capitalize(name)
+  return 'kPlatform' + name.capitalize()
 
 
 def GeneratePlatformListText(out, platforms):
@@ -149,9 +152,9 @@ def main(argv):
     platforms.insert(0, options.default)
 
   # Write to standard output or file specified by --output_{cc,h}.
-  out_cc = sys.stdout
-  out_h = sys.stdout
-  out_txt = sys.stdout
+  out_cc = getattr(sys.stdout, 'buffer', sys.stdout)
+  out_h = getattr(sys.stdout, 'buffer', sys.stdout)
+  out_txt = getattr(sys.stdout, 'buffer', sys.stdout)
   if options.output_cc:
     out_cc = open(options.output_cc, 'wb')
   if options.output_h:
@@ -159,9 +162,16 @@ def main(argv):
   if options.output_txt:
     out_txt = open(options.output_txt, 'wb')
 
-  GeneratePlatformListText(out_txt, platforms)
-  GeneratePlatformListHeader(out_h, platforms)
-  GeneratePlatformListSource(out_cc, platforms)
+  out_txt_str = StringIO()
+  out_h_str = StringIO()
+  out_cc_str = StringIO()
+
+  GeneratePlatformListText(out_txt_str, platforms)
+  out_txt.write(out_txt_str.getvalue().encode('utf-8'))
+  GeneratePlatformListHeader(out_h_str, platforms)
+  out_h.write(out_h_str.getvalue().encode('utf-8'))
+  GeneratePlatformListSource(out_cc_str, platforms)
+  out_cc.write(out_cc_str.getvalue().encode('utf-8'))
 
   if options.output_cc:
     out_cc.close()