Add BackgroundModeOptimizer that can restart the browser

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 1563 matching lines @@
       'browser/background/background_contents_service.cc',
       'browser/background/background_contents_service.h',
       'browser/background/background_contents_service_factory.cc',
       'browser/background/background_contents_service_factory.h',
       'browser/background/background_mode_manager.cc',
       'browser/background/background_mode_manager.h',
       'browser/background/background_mode_manager_aura.cc',
       'browser/background/background_mode_manager_chromeos.cc',
       'browser/background/background_mode_manager_mac.mm',
       'browser/background/background_mode_manager_win.cc',
+      'browser/background/background_mode_optimizer.cc',
+      'browser/background/background_mode_optimizer.h',
       'browser/background/background_trigger.h',
     ],
     'chrome_browser_bookmark_sources': [
       'browser/bookmarks/bookmark_model_factory.cc',
       'browser/bookmarks/bookmark_model_factory.h',
       'browser/bookmarks/bookmark_stats.cc',
       'browser/bookmarks/bookmark_stats.h',
       'browser/bookmarks/chrome_bookmark_client.cc',
       'browser/bookmarks/chrome_bookmark_client.h',
       'browser/bookmarks/managed_bookmark_service_factory.cc',
@@ skipping 2755 matching lines @@
             '../components/components.gyp:rlz',
             '../components/components.gyp:search_engines',
             '../rlz/rlz.gyp:rlz_lib',
             'common',
           ],
         },
       ],
     }],
   ],
 }