Set extension-related webkit preferences in a common location.

chrome/chrome_browser.gypi

 # Copyright (c) 2011 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'dependencies': [
@@ skipping 1167 matching lines @@
         'browser/extensions/extension_uninstall_dialog.cc',
         'browser/extensions/extension_uninstall_dialog.h',
         'browser/extensions/extension_updater.cc',
         'browser/extensions/extension_updater.h',
         'browser/extensions/extension_warning_set.cc',
         'browser/extensions/extension_warning_set.h',
         'browser/extensions/extension_web_socket_proxy_private_api.cc',
         'browser/extensions/extension_web_socket_proxy_private_api.h',
         'browser/extensions/extension_web_ui.cc',
         'browser/extensions/extension_web_ui.h',
+        'browser/extensions/extension_webkit_preferences.cc',
+        'browser/extensions/extension_webkit_preferences.h',
         'browser/extensions/extension_webnavigation_api.cc',
         'browser/extensions/extension_webnavigation_api.h',
         'browser/extensions/extension_webnavigation_api_constants.cc',
         'browser/extensions/extension_webnavigation_api_constants.h',
         'browser/extensions/extension_webrequest_api.cc',
         'browser/extensions/extension_webrequest_api.h',
         'browser/extensions/extension_webrequest_api_constants.cc',
         'browser/extensions/extension_webrequest_api_constants.h',
         'browser/extensions/extension_webrequest_time_tracker.cc',
         'browser/extensions/extension_webrequest_time_tracker.h',
@@ skipping 4022 matching lines @@
       'type': 'static_library',
       'sources': [ 'browser/history/in_memory_url_index_cache.proto' ],
       'variables': {
         'proto_in_dir': 'browser/history',
         'proto_out_dir': 'chrome/browser/history',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }