Use WebKit compositor in ui::Layer

ui/aura/aura.gyp

 # Copyright (c) 2011 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 93 matching lines @@
       ],
     },
     {
       'target_name': 'aura_unittests',
       'type': 'executable',
       'dependencies': [
         '../../base/base.gyp:test_support_base',
         '../../skia/skia.gyp:skia',
         '../../testing/gtest.gyp:gtest',
         '../gfx/compositor/compositor.gyp:compositor',
+        '../gfx/compositor/compositor.gyp:compositor_test_support',
         '../gfx/gl/gl.gyp:gl',
         '../ui.gyp:gfx_resources',
         '../ui.gyp:ui',
         '../ui.gyp:ui_resources',
         'test_support_aura',
         'aura',
       ],
       'include_dirs': [
         '..',
       ],
@@ skipping 17 matching lines @@
         }],
         ['OS!="mac"', {
           'dependencies': [
             '../../chrome/chrome.gyp:packed_resources',
            ],
         }],
       ],
     },
   ],
 }