Patch from https://codereview.chromium.org/11111005/ without actual file deletes

cc/threaded_unittest.h

 // Copyright 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.
 
 #ifndef CCThreadedTest_h
 #define CCThreadedTest_h
 
 #include "CCLayerTreeHost.h"
 #include "CCLayerTreeHostImpl.h"
 #include "CCScopedThreadProxy.h"
 #include "CompositorFakeWebGraphicsContext3D.h"
 #include "base/hash_tables.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include <public/WebAnimationDelegate.h>
 #include <public/WebThread.h>
 
 namespace cc {
 class CCLayerImpl;
 class CCLayerTreeHost;
 class CCLayerTreeHostClient;
 class CCLayerTreeHostImpl;
-class GraphicsContext3D;
 }
 
 namespace WebKitTests {
 
 // Used by test stubs to notify the test when something interesting happens.
 class TestHooks : public WebKit::WebAnimationDelegate {
 public:
     virtual void beginCommitOnCCThread(cc::CCLayerTreeHostImpl*) { }
     virtual void commitCompleteOnCCThread(cc::CCLayerTreeHostImpl*) { }
     virtual bool prepareToDrawOnCCThread(cc::CCLayerTreeHostImpl*);
@@ skipping 166 matching lines @@
     TEST_F(TEST_FIXTURE_NAME, runSingleThread)            \
     {                                                     \
         runTest(false);                                   \
     }                                                     \
     TEST_F(TEST_FIXTURE_NAME, runMultiThread)             \
     {                                                     \
         runTest(true);                                    \
     }
 
 #endif // CCThreadedTest_h