Introduce ES6 iterator for DOM objects.

Source/bindings/core/v8/custom/custom.gypi

 # 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.
 
 {
     'variables': {
         'bindings_core_v8_custom_files': [
             'V8ArrayBufferCustom.cpp',
             'V8ArrayBufferCustom.h',
             'V8ArrayBufferViewCustom.cpp',
@@ skipping 56 matching lines @@
             'V8Uint8ArrayCustom.h',
             'V8Uint8ClampedArrayCustom.h',
             'V8WebGLRenderingContextCustom.cpp',
             'V8WebKitPointCustom.cpp',
             'V8WindowCustom.cpp',
             'V8WorkerCustom.cpp',
             'V8WorkerGlobalScopeCustom.cpp',
             'V8XMLHttpRequestCustom.cpp',
             'V8XSLTProcessorCustom.cpp',
         ],
+        'bindings_core_v8_custom_testing_files': [
+            'V8InternalsCustom.cpp',
+        ],
     },
 }