Use dictionaries for context creation attributes. Eliminate custom bindings.

Source/bindings/scripts/v8_dictionary.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generate template contexts of dictionaries for both v8 bindings and
 implementation classes that are used by blink's core/modules.
 """
 
 import operator
 from idl_types import IdlType
@@ skipping 41 matching lines @@
 def dictionary_context(dictionary, interfaces_info):
     includes.clear()
     includes.update(DICTIONARY_CPP_INCLUDES)
     cpp_class = v8_utilities.cpp_name(dictionary)
     context = {
         'cpp_class': cpp_class,
         'header_includes': set(DICTIONARY_H_INCLUDES),
         'members': [member_context(member)
                     for member in sorted(dictionary.members,
                                          key=operator.attrgetter('name'))],
+        'use_permissive_dictionary_conversion': 'PermissiveDictionaryConversion' in dictionary.extended_attributes,
         'v8_class': v8_types.v8_type(cpp_class),
         'v8_original_class': v8_types.v8_type(dictionary.name),
     }
     if dictionary.parent:
         IdlType(dictionary.parent).add_includes_for_type()
         parent_cpp_class = v8_utilities.cpp_name_from_interfaces_info(
             dictionary.parent, interfaces_info)
         context.update({
             'parent_cpp_class': parent_cpp_class,
             'parent_v8_class': v8_types.v8_type(parent_cpp_class),
@@ skipping 102 matching lines @@
         'getter_expression': getter_expression(),
         'has_method_expression': has_method_expression(),
         'has_method_name': has_method_name_for_dictionary_member(member),
         'is_object': is_object,
         'is_traceable': idl_type.is_traceable,
         'member_cpp_type': member_cpp_type(),
         'null_setter_name': null_setter_name_for_dictionary_member(member),
         'rvalue_cpp_type': idl_type.cpp_type_args(used_as_rvalue_type=True),
         'setter_name': setter_name_for_dictionary_member(member),
     }