Refactor MutatorHostClient from LayerTreeHost to LayerTree.

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(std::unique_ptr<base::Value> value,
                         const DoneCallback& callback);
   ~UnittestOnlyBenchmark() override;
 
-  void DidUpdateLayers(LayerTreeHost* host) override;
+  void DidUpdateLayers(LayerTree* layer_tree) override;
   bool ProcessMessage(std::unique_ptr<base::Value> value) override;
 
  protected:
   std::unique_ptr<MicroBenchmarkImpl> CreateBenchmarkImpl(
       scoped_refptr<base::SingleThreadTaskRunner> origin_task_runner) override;
 
  private:
   void RecordImplResults(std::unique_ptr<base::Value> results);
 
   bool create_impl_benchmark_;
   base::WeakPtrFactory<UnittestOnlyBenchmark> weak_ptr_factory_;
 };
 
 }  // namespace cc
 
 #endif  // CC_DEBUG_UNITTEST_ONLY_BENCHMARK_H_