Added proper extension manifest parser for launcher_page.

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 115 matching lines @@
         'common/manifest_handlers/externally_connectable.cc',
         'common/manifest_handlers/externally_connectable.h',
         'common/manifest_handlers/file_handler_info.cc',
         'common/manifest_handlers/file_handler_info.h',
         'common/manifest_handlers/icons_handler.cc',
         'common/manifest_handlers/icons_handler.h',
         'common/manifest_handlers/incognito_info.cc',
         'common/manifest_handlers/incognito_info.h',
         'common/manifest_handlers/kiosk_mode_info.cc',
         'common/manifest_handlers/kiosk_mode_info.h',
+        'common/manifest_handlers/launcher_page_info.cc',
+        'common/manifest_handlers/launcher_page_info.h',
         'common/manifest_handlers/offline_enabled_info.cc',
         'common/manifest_handlers/offline_enabled_info.h',
         'common/manifest_handlers/permissions_parser.cc',
         'common/manifest_handlers/permissions_parser.h',
         'common/manifest_handlers/requirements_info.cc',
         'common/manifest_handlers/requirements_info.h',
         'common/manifest_handlers/sandboxed_page_info.cc',
         'common/manifest_handlers/sandboxed_page_info.h',
         'common/manifest_handlers/shared_module_info.cc',
         'common/manifest_handlers/shared_module_info.h',
@@ skipping 780 matching lines @@
           'browser/api/cast_channel/logging.proto'
       ],
       'variables': {
           'proto_in_dir': 'browser/api/cast_channel',
           'proto_out_dir': 'extensions/browser/api/cast_channel',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ]
 }