mac: ensure ui::Compositor exists for visible RWHVs

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 971 matching lines @@
         ['use_aura==1 or OS=="mac"', {
           'sources': [
             'browser/compositor/test/no_transport_image_transport_factory.cc',
             'browser/compositor/test/no_transport_image_transport_factory.h',
           ],
           'dependencies': [
             '../ui/compositor/compositor.gyp:compositor',
             '../third_party/libvpx/libvpx.gyp:libvpx',
           ],
         }],
+        ['OS=="mac"', {
+          'dependencies': [
+            '../ui/accelerated_widget_mac/accelerated_widget_mac.gyp:accelerated_widget_mac',
+          ],
+        }],
         ['OS=="android"', {
           'dependencies': [
             '../ui/android/ui_android.gyp:ui_android',
             '../ui/shell_dialogs/shell_dialogs.gyp:shell_dialogs',
             'content.gyp:content_shell_assets_copy',
           ],
         }],
         ['v8_use_external_startup_data==1', {
           'dependencies': [
             '../gin/gin.gyp:gin',
@@ skipping 927 matching lines @@
                   'content_unittests_apk.isolate',
                 ],
               },
             ],
           },
         ],
       ],
     }],
   ],
 }