Implement sidebar support for extension action popups

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 676 matching lines @@
       'browser/search/suggestions/suggestions_source.h',
       'browser/search/thumbnail_source.cc',
       'browser/search/thumbnail_source.h',
       'browser/searuch/most_visited_iframe_source.h',
       'browser/shell_integration.cc',
       'browser/shell_integration.h',
       'browser/shell_integration_android.cc',
       'browser/shell_integration_chromeos.cc',
       'browser/shell_integration_mac.mm',
       'browser/shell_integration_win.cc',
+      'browser/sidebar/sidebar_container.cc',
+      'browser/sidebar/sidebar_container.h',
+      'browser/sidebar/sidebar_manager.cc',
+      'browser/sidebar/sidebar_manager.h',
+      'browser/sidebar/sidebar_manager_observer.h',
       'browser/site_details.cc',
       'browser/site_details.h',
       'browser/speech/chrome_speech_recognition_manager_delegate.cc',
       'browser/speech/chrome_speech_recognition_manager_delegate.h',
       'browser/speech/tts_android.cc',
       'browser/speech/tts_android.h',
       'browser/speech/tts_chromeos.cc',
       'browser/speech/tts_controller.h',
       'browser/speech/tts_controller_impl.cc',
       'browser/speech/tts_controller_impl.h',
@@ skipping 3215 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' ]
         },
       ],
     },],
   ],
 }