Implement PermissionService::GetNextPermissionChange.

chrome/chrome_tests_unit.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': {
     'chrome_unit_tests_sources': [
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.h',
       '../components/autofill/content/renderer/test_password_generation_agent.cc',
       '../components/autofill/content/renderer/test_password_generation_agent.h',
@@ skipping 56 matching lines @@
       'browser/content_settings/content_settings_mock_observer.h',
       'browser/content_settings/content_settings_origin_identifier_value_map_unittest.cc',
       'browser/content_settings/content_settings_policy_provider_unittest.cc',
       'browser/content_settings/content_settings_pref_provider_unittest.cc',
       'browser/content_settings/content_settings_usages_state_unittest.cc',
       'browser/content_settings/cookie_settings_unittest.cc',
       'browser/content_settings/host_content_settings_map_unittest.cc',
       'browser/content_settings/mock_settings_observer.cc',
       'browser/content_settings/mock_settings_observer.h',
       'browser/content_settings/permission_context_base_unittest.cc',
+      'browser/content_settings/permission_observer_unittest.cc',
       'browser/content_settings/permission_queue_controller_unittest.cc',
       'browser/content_settings/tab_specific_content_settings_unittest.cc',
       'browser/custom_handlers/protocol_handler_registry_unittest.cc',
       'browser/devtools/device/webrtc/devtools_bridge_instances_request_unittest.cc',
       'browser/devtools/devtools_network_controller_unittest.cc',
       'browser/download/all_download_item_notifier_unittest.cc',
       'browser/download/chrome_download_manager_delegate_unittest.cc',
       'browser/download/download_history_unittest.cc',
       'browser/download/download_item_model_unittest.cc',
       'browser/download/download_path_reservation_tracker_unittest.cc',
@@ skipping 2674 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }