Make ui_chromeos_resources IDRs accessible via chrome://theme/<IDR>.

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 2344 matching lines @@
             'browser/media/webrtc_log_uploader_unittest.cc',
             'browser/media/webrtc_log_util_unittest.cc',
             'browser/media/webrtc_rtp_dump_handler_unittest.cc',
             'browser/media/webrtc_rtp_dump_writer_unittest.cc',
             'renderer/media/chrome_webrtc_log_message_delegate_unittest.cc',
           ],
         }],
         ['chromeos==1', {
           'dependencies': [
             '../ash/ash_resources.gyp:ash_resources',
+            '../ui/chromeos/ui_chromeos.gyp:ui_chromeos_resources',
           ],
           'sources!': [
             'browser/extensions/api/messaging/native_message_process_host_unittest.cc',
             'browser/extensions/api/messaging/native_messaging_host_manifest_unittest.cc',
             'browser/extensions/api/messaging/native_messaging_policy_handler_unittest.cc',
             'browser/password_manager/native_backend_gnome_x_unittest.cc',
             'browser/password_manager/native_backend_kwallet_x_unittest.cc',
             'browser/policy/cloud/user_policy_signin_service_unittest.cc',
             'browser/profiles/profile_list_desktop_unittest.cc',
             'browser/safe_browsing/download_protection_service_unittest.cc',
@@ skipping 564 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }