Remove parts of //cc we aren't using

cc/debug/unittest_only_benchmark.h

-// Copyright 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.
-
-#ifndef CC_DEBUG_UNITTEST_ONLY_BENCHMARK_H_
-#define CC_DEBUG_UNITTEST_ONLY_BENCHMARK_H_
-
-#include "base/memory/weak_ptr.h"
-#include "cc/debug/micro_benchmark.h"
-
-namespace cc {
-
-class CC_EXPORT UnittestOnlyBenchmark : public MicroBenchmark {
- public:
-  UnittestOnlyBenchmark(scoped_ptr<base::Value> value,
-                        const DoneCallback& callback);
-  ~UnittestOnlyBenchmark() override;
-
-  void DidUpdateLayers(LayerTreeHost* host) override;
-  bool ProcessMessage(scoped_ptr<base::Value> value) override;
-
- protected:
-  scoped_ptr<MicroBenchmarkImpl> CreateBenchmarkImpl(
-      scoped_refptr<base::MessageLoopProxy> origin_loop) override;
-
- private:
-  void RecordImplResults(scoped_ptr<base::Value> results);
-
-  bool create_impl_benchmark_;
-  base::WeakPtrFactory<UnittestOnlyBenchmark> weak_ptr_factory_;
-};
-
-}  // namespace cc
-
-#endif  // CC_DEBUG_UNITTEST_ONLY_BENCHMARK_H_