Use base::FooValue::From() to simplify gpu code.

gpu/tools/compositor_model_bench/render_models.h

 // 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.
 
 // Define the interface for a generic simulation, and a factory method for
 // instantiating different models.
 
 #ifndef GPU_TOOLS_COMPOSITOR_MODEL_BENCH_RENDER_MODELS_H_
 #define GPU_TOOLS_COMPOSITOR_MODEL_BENCH_RENDER_MODELS_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "gpu/tools/compositor_model_bench/render_tree.h"
 
 enum RenderModel {
   ForwardRenderModel
 };
 
 const char* ModelToString(RenderModel m);
 
 class RenderModelSimulator {
  public:
   virtual ~RenderModelSimulator();
   virtual void Update() = 0;
   virtual void Resize(int width, int height) = 0;
 
  protected:
-  explicit RenderModelSimulator(RenderNode* root);
+  explicit RenderModelSimulator(std::unique_ptr<RenderNode> root);
+
   std::unique_ptr<RenderNode> root_;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(RenderModelSimulator);
 };
 
-RenderModelSimulator* ConstructSimulationModel(RenderModel model,
-                                               RenderNode* render_tree_root,
-                                               int window_width,
-                                               int window_height);
+std::unique_ptr<RenderModelSimulator> ConstructSimulationModel(
+    RenderModel model,
+    std::unique_ptr<RenderNode> render_tree_root,
+    int window_width,
+    int window_height);
 
 #endif  // GPU_TOOLS_COMPOSITOR_MODEL_BENCH_RENDER_MODELS_H_