Remove parts of //cc we aren't using

cc/debug/unittest_only_benchmark_impl.cc

-// 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.
-
-#include "cc/debug/unittest_only_benchmark_impl.h"
-
-#include "base/message_loop/message_loop_proxy.h"
-#include "base/values.h"
-
-namespace cc {
-
-UnittestOnlyBenchmarkImpl::UnittestOnlyBenchmarkImpl(
-    scoped_refptr<base::MessageLoopProxy> origin_loop,
-    base::Value* settings,
-    const DoneCallback& callback)
-    : MicroBenchmarkImpl(callback, origin_loop) {}
-
-UnittestOnlyBenchmarkImpl::~UnittestOnlyBenchmarkImpl() {}
-
-void UnittestOnlyBenchmarkImpl::DidCompleteCommit(LayerTreeHostImpl* host) {
-  NotifyDone(nullptr);
-}
-
-}  // namespace cc