Remove unused MockMediaObserver

content/content_tests.gypi

 # Copyright (c) 2013 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': {
     'layouttest_support_content_sources': [
       'public/test/layouttest_support.h',
       'public/test/nested_message_pump_android.cc',
       'public/test/nested_message_pump_android.h',
       'test/layouttest_support.cc',
       'test/test_media_stream_renderer_factory.cc',
       'test/test_media_stream_renderer_factory.h',
       'test/test_video_frame_provider.cc',
       'test/test_video_frame_provider.h',
     ],
     'test_support_content_sources': [
       # TODO(phajdan.jr): All of those files should live in content/test (if
       # they're only used by content) or content/public/test (if they're used
       # by other embedders).
       'browser/download/mock_download_file.cc',
       'browser/download/mock_download_file.h',
       'browser/geolocation/fake_access_token_store.cc',
       'browser/geolocation/fake_access_token_store.h',
       'browser/geolocation/mock_location_arbitrator.cc',
       'browser/geolocation/mock_location_arbitrator.h',
       'browser/geolocation/mock_location_provider.cc',
       'browser/geolocation/mock_location_provider.h',
-      'browser/renderer_host/media/mock_media_observer.cc',
-      'browser/renderer_host/media/mock_media_observer.h',
       'public/test/async_file_test_helper.cc',
       'public/test/async_file_test_helper.h',
       'public/test/browser_test.h',
       'public/test/browser_test_base.cc',
       'public/test/browser_test_base.h',
       'public/test/browser_test_utils.cc',
       'public/test/browser_test_utils.h',
       'public/test/content_browser_sanity_checker.cc',
       'public/test/content_browser_sanity_checker.h',
       'public/test/content_test_suite_base.cc',
@@ skipping 2118 matching lines @@
                   'files': ['<(PRODUCT_DIR)/libnpapi_test_plugin.so'],
                 },
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }