Extract renderer-side favicon downloading code into separate helper class

chrome/chrome_renderer.gypi

 # Copyright (c) 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.
 
 {
   'targets': [
     {
       'target_name': 'renderer',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 117 matching lines @@
         'renderer/extensions/user_script_scheduler.cc',
         'renderer/extensions/user_script_scheduler.h',
         'renderer/extensions/user_script_slave.cc',
         'renderer/extensions/user_script_slave.h',
         'renderer/extensions/v8_schema_registry.cc',
         'renderer/extensions/v8_schema_registry.h',
         'renderer/extensions/web_request_custom_bindings.cc',
         'renderer/extensions/web_request_custom_bindings.h',
         'renderer/extensions/webstore_bindings.cc',
         'renderer/extensions/webstore_bindings.h',
+        'renderer/favicon_helper.cc',
+        'renderer/favicon_helper.h',
         'renderer/frame_sniffer.cc',
         'renderer/frame_sniffer.h',
         'renderer/loadtimes_extension_bindings.h',
         'renderer/loadtimes_extension_bindings.cc',
         'renderer/net/predictor_queue.cc',
         'renderer/net/predictor_queue.h',
         'renderer/net/renderer_net_predictor.cc',
         'renderer/net/renderer_net_predictor.h',
         'renderer/playback_extension.cc',
         'renderer/playback_extension.h',
@@ skipping 183 matching lines @@
               'export_dependent_settings': [
                 '<(allocator_target)',
               ],
             }],
           ],
         }],
       ],
     },
   ],
 }