Add AshDesktopMediaList and enable Desktop Capture API on Chrome OS.

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.
 {
   'targets': [
     {
       # This target contains mocks and test utilities that don't belong in
       # production libraries but are used by more than one test executable.
       'target_name': 'test_support_common',
       'type': 'static_library',
@@ skipping 996 matching lines @@
         'browser/local_discovery/service_discovery_client_mac_unittest.mm',
         'browser/logging_chrome_unittest.cc',
         'browser/mac/keystone_glue_unittest.mm',
         'browser/managed_mode/managed_mode_url_filter_unittest.cc',
         'browser/managed_mode/managed_user_service_unittest.cc',
         'browser/managed_mode/managed_user_sync_service_unittest.cc',
         'browser/managed_mode/managed_user_refresh_token_fetcher_unittest.cc',
         'browser/managed_mode/managed_user_registration_utility_unittest.cc',
         'browser/managed_mode/managed_user_settings_service_unittest.cc',
         'browser/managed_mode/supervised_user_pref_store_unittest.cc',
+        'browser/media/ash_desktop_media_list_unittest.cc',
         'browser/media/native_desktop_media_list_unittest.cc',
         'browser/media/webrtc_log_uploader_unittest.cc',
         'browser/media_galleries/fileapi/native_media_file_util_unittest.cc',
         'browser/media_galleries/linux/mtp_device_object_enumerator_unittest.cc',
         'browser/media_galleries/mac/mtp_device_delegate_impl_mac_unittest.mm',
         'browser/media_galleries/win/mtp_device_delegate_impl_win_unittest.cc',
         'browser/media_galleries/media_file_system_registry_unittest.cc',
         'browser/media_galleries/media_galleries_dialog_controller_mock.cc',
         'browser/media_galleries/media_galleries_dialog_controller_mock.h',
         'browser/media_galleries/media_galleries_permissions_unittest.cc',
@@ skipping 1883 matching lines @@
             'browser/ui/app_list/test/fake_profile_store.h',
             'browser/ui/app_list/test/fast_show_pickler_unittest.cc',
             'browser/ui/views/app_list/linux/app_list_linux_unittest.cc',
             'browser/ui/views/app_list/win/app_list_win_unittest.cc',
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }