Add a metrics extensions API....

chrome/chrome_browser.gypi

 # Copyright (c) 2010 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': '<(library)',
       'msvs_guid': '5BF908A7-68FB-4A4B-99E3-8C749F1FE4EA',
@@ skipping 862 matching lines @@
         'browser/extensions/extension_host.cc',
         'browser/extensions/extension_host.h',
         'browser/extensions/extension_host_mac.h',
         'browser/extensions/extension_host_mac.mm',
         'browser/extensions/extension_i18n_api.cc',
         'browser/extensions/extension_i18n_api.h',
         'browser/extensions/extension_install_ui.cc',
         'browser/extensions/extension_install_ui.h',
         'browser/extensions/extension_message_service.cc',
         'browser/extensions/extension_message_service.h',
+        'browser/extensions/extension_metrics_module.cc',
+        'browser/extensions/extension_metrics_module.h',
         'browser/extensions/extension_page_actions_module.cc',
         'browser/extensions/extension_page_actions_module.h',
         'browser/extensions/extension_page_actions_module_constants.cc',
         'browser/extensions/extension_page_actions_module_constants.h',
         'browser/extensions/extension_popup_api.cc',
         'browser/extensions/extension_popup_api.h',
         'browser/extensions/extension_popup_host.cc',
         'browser/extensions/extension_popup_host.h',
         'browser/extensions/extension_prefs.cc',
         'browser/extensions/extension_prefs.h',
@@ skipping 1923 matching lines @@
       ],
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: