Declarative resource hints go through mojo IPC to //content

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',
@@ skipping 222 matching lines @@
       'browser/host_zoom_map_impl_browsertest.cc',
       'browser/iframe_zoom_browsertest.cc',
       'browser/indexed_db/indexed_db_browsertest.cc',
       'browser/indexed_db/mock_browsertest_indexed_db_class_factory.cc',
       'browser/indexed_db/mock_browsertest_indexed_db_class_factory.h',
       'browser/loader/async_resource_handler_browsertest.cc',
       'browser/loader/async_revalidation_manager_browsertest.cc',
       'browser/loader/cross_site_resource_handler_browsertest.cc',
       'browser/loader/reload_cache_control_browsertest.cc',
       'browser/loader/resource_dispatcher_host_browsertest.cc',
+      'browser/loader/resource_hints_browsertest.cc',
       'browser/manifest/manifest_browsertest.cc',
       'browser/media/encrypted_media_browsertest.cc',
       'browser/media/media_browsertest.cc',
       'browser/media/media_browsertest.h',
       'browser/media/media_canplaytype_browsertest.cc',
       'browser/media/media_source_browsertest.cc',
       'browser/media/midi_browsertest.cc',
       'browser/media/session/media_session_browsertest.cc',
       'browser/media/session/media_session_delegate_default_browsertest.cc',
       'browser/media/session/media_session_visibility_browsertest.cc',
@@ skipping 1670 matching lines @@
                   'content_unittests_apk.isolate',
                 ],
               },
             ],
           },
         ],
       ],
     }],
   ],
 }