gin: Add the concept of named and indexed interceptors.

gin/gin.gyp

 # Copyright 2013 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 17 matching lines @@
         'array_buffer.h',
         'context_holder.cc',
         'converter.cc',
         'converter.h',
         'dictionary.cc',
         'dictionary.h',
         'function_template.cc',
         'function_template.h',
         'gin_export.h',
         'handle.h',
+        'interceptor.cc',
+        'interceptor.h',
         'isolate_holder.cc',
         'modules/console.cc',
         'modules/console.h',
         'modules/file_module_provider.cc',
         'modules/file_module_provider.h',
         'modules/module_registry.cc',
         'modules/module_registry.h',
         'modules/module_registry_observer.h',
         'modules/module_runner_delegate.cc',
         'modules/module_runner_delegate.h',
@@ skipping 62 matching lines @@
     {
       'target_name': 'gin_unittests',
       'type': 'executable',
       'dependencies': [
         '../base/base.gyp:run_all_unittests',
         '../v8/tools/gyp/v8.gyp:v8',
         'gin_test',
       ],
       'sources': [
         'converter_unittest.cc',
+        'interceptor_unittest.cc',
         'modules/module_registry_unittest.cc',
         'modules/timer_unittest.cc',
         'per_context_data_unittest.cc',
         'shell_runner_unittest.cc',
         'test/run_all_unittests.cc',
         'test/run_js_tests.cc',
         'wrappable_unittest.cc',
       ],
     },
   ],
 }