WIP bindings: Add support for the record<K,V> WebIDL type.

third_party/WebKit/Source/bindings/scripts/v8_callback_function.py

 # Copyright 2016 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 values for a callback function.
 
 Design doc: http://www.chromium.org/developers/design-documents/idl-compiler
 """
 
 from v8_globals import includes  # pylint: disable=W0403
 import v8_utilities  # pylint: disable=W0403
 
 CALLBACK_FUNCTION_H_INCLUDES = frozenset([
+    'bindings/core/v8/NativeValueTraits.h',
     'bindings/core/v8/ScriptWrappable.h',
     'bindings/core/v8/TraceWrapperV8Reference.h',
     'platform/heap/Handle.h',
     'wtf/text/WTFString.h',
 ])
 CALLBACK_FUNCTION_CPP_INCLUDES = frozenset([
     'bindings/core/v8/ExceptionState.h',
     'bindings/core/v8/ScriptState.h',
     'bindings/core/v8/ToV8.h',
     'bindings/core/v8/V8Binding.h',
@@ skipping 49 matching lines @@
     ]
     argument_declarations.extend(
         '%s %s' % (argument.idl_type.callback_cpp_type, argument.name)
         for argument in arguments)
     if return_cpp_type:
         argument_declarations.append('%s returnValue' % return_cpp_type)
     return {
         'argument_declarations': argument_declarations,
         'arguments': [argument_context(argument) for argument in arguments],
     }