Implement PermissionService::GetNextPermissionChange.

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 1294 matching lines @@
       'browser/content_settings/chrome_content_settings_client.cc',
       'browser/content_settings/chrome_content_settings_client.h',
       'browser/content_settings/chrome_content_settings_utils.cc',
       'browser/content_settings/chrome_content_settings_utils.h',
       'browser/content_settings/cookie_settings.cc',
       'browser/content_settings/cookie_settings.h',
       'browser/content_settings/local_shared_objects_container.cc',
       'browser/content_settings/local_shared_objects_container.h',
       'browser/content_settings/permission_bubble_request_impl.cc',
       'browser/content_settings/permission_bubble_request_impl.h',
+      'browser/content_settings/permission_context.cc',
+      'browser/content_settings/permission_context.h',
       'browser/content_settings/permission_context_base.cc',
       'browser/content_settings/permission_context_base.h',
       'browser/content_settings/permission_context_uma_util.cc',
       'browser/content_settings/permission_context_uma_util.h',
       'browser/content_settings/permission_infobar_delegate.cc',
       'browser/content_settings/permission_infobar_delegate.h',
+      'browser/content_settings/permission_observer.cc',
+      'browser/content_settings/permission_observer.h',
+      'browser/content_settings/permission_observer_factory.cc',
+      'browser/content_settings/permission_observer_factory.h',
       'browser/content_settings/permission_queue_controller.cc',
       'browser/content_settings/permission_queue_controller.h',
       'browser/content_settings/tab_specific_content_settings.cc',
       'browser/content_settings/tab_specific_content_settings.h',
       'browser/content_settings/web_site_settings_uma_util.cc',
       'browser/content_settings/web_site_settings_uma_util.h',
     ],
     'chrome_browser_extensions_sources': [
       'browser/accessibility/accessibility_extension_api.cc',
       'browser/accessibility/accessibility_extension_api.h',
@@ skipping 2428 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' ]
         },
       ],
     },],
   ],
 }