Remove MetricsServiceObserver in favor of MetricsProvider.

chrome/chrome_browser.gypi

 # Copyright 2012 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': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 226 matching lines @@
       'browser/chrome_browser_main.h',
       'browser/chrome_browser_main_android.cc',
       'browser/chrome_browser_main_android.h',
       'browser/chrome_browser_main_extra_parts.h',
       'browser/chrome_browser_main_linux.cc',
       'browser/chrome_browser_main_linux.h',
       'browser/chrome_browser_main_mac.h',
       'browser/chrome_browser_main_mac.mm',
       'browser/chrome_browser_main_win.cc',
       'browser/chrome_browser_main_win.h',
-      'browser/chrome_browser_metrics_service_observer.cc',
-      'browser/chrome_browser_metrics_service_observer.h',
       'browser/chrome_content_browser_client.cc',
       'browser/chrome_content_browser_client.h',
       'browser/chrome_content_browser_client_parts.h',
       'browser/chrome_elf_init_win.cc',
       'browser/chrome_elf_init_win.h',
       'browser/chrome_notification_types.h',
       'browser/chrome_page_zoom.cc',
       'browser/chrome_page_zoom.h',
       'browser/chrome_page_zoom_constants.cc',
       'browser/chrome_page_zoom_constants.h',
@@ skipping 3313 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/sync_file_system/drive_backend',
             'proto_out_dir': 'chrome/browser/sync_file_system/drive_backend',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],
   ],
 }