Create ExtensionsRendererClient.

extensions/extensions.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 401 matching lines @@
       'target_name': 'extensions_renderer',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'sources': [
         'renderer/console.cc',
         'renderer/console.h',
         'renderer/event_bindings.cc',
         'renderer/event_bindings.h',
+        'renderer/extensions_renderer_client.cc',
+        'renderer/extensions_renderer_client.h',
         'renderer/module_system.cc',
         'renderer/module_system.h',
         'renderer/native_handler.cc',
         'renderer/native_handler.h',
         'renderer/object_backed_native_handler.cc',
         'renderer/object_backed_native_handler.h',
         'renderer/request_sender.cc',
         'renderer/request_sender.h',
         'renderer/safe_builtins.cc',
         'renderer/safe_builtins.h',
@@ skipping 68 matching lines @@
         'test/test_extensions_client.cc',
         'test/test_extensions_client.h',
         'test/test_permission_message_provider.cc',
         'test/test_permission_message_provider.h',
         'test/test_permissions_provider.cc',
         'test/test_permissions_provider.h',
       ],
     },
   ]
 }