Add support for (de)serializing LayerTreeHost.

cc/trees/layer_tree_host.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 CC_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 54 matching lines @@
 class ResourceProvider;
 class ResourceUpdateQueue;
 class SharedBitmapManager;
 class TaskGraphRunner;
 class TopControlsManager;
 class UIResourceRequest;
 struct PendingPageScaleAnimation;
 struct RenderingStats;
 struct ScrollAndScaleSet;
 
+namespace proto {
+class LayerTreeHost;
+}
+
 class CC_EXPORT LayerTreeHost : public MutatorHostClient {
  public:
   // TODO(sad): InitParams should be a movable type so that it can be
   // std::move()d to the Create* functions.
   struct CC_EXPORT InitParams {
     LayerTreeHostClient* client = nullptr;
     SharedBitmapManager* shared_bitmap_manager = nullptr;
     gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager = nullptr;
     TaskGraphRunner* task_graph_runner = nullptr;
     LayerTreeSettings const* settings = nullptr;
@@ skipping 274 matching lines @@
   bool HasOnlyTranslationTransforms(const Layer* layer) const;
   bool MaximumTargetScale(const Layer* layer, float* max_scale) const;
   bool AnimationStartScale(const Layer* layer, float* start_scale) const;
   bool HasAnyAnimationTargetingProperty(
       const Layer* layer,
       Animation::TargetProperty property) const;
   bool AnimationsPreserveAxisAlignment(const Layer* layer) const;
   bool HasAnyAnimation(const Layer* layer) const;
   bool HasActiveAnimation(const Layer* layer) const;
 
+  // Serializes the parts of this LayerTreeHost that is needed for a commit to a
+  // protobuf message. Not all members are serialized as they are not helpful
+  // for remote usage.
+  void ToProtobufForCommit(proto::LayerTreeHost* proto) const;
+
+  // Deserializes the protobuf into this LayerTreeHost before a commit. The
+  // expected input is a serialized remote LayerTreeHost. After deserializing
+  // the protobuf, the normal commit-flow should continue.
+  void FromProtobufForCommit(const proto::LayerTreeHost& proto);
+
  protected:
   LayerTreeHost(InitParams* params, CompositorMode mode);
   void InitializeThreaded(
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
   void InitializeSingleThreaded(
       LayerTreeHostSingleThreadClient* single_thread_client,
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
@@ skipping 18 matching lines @@
   }
   TaskGraphRunner* task_graph_runner() const { return task_graph_runner_; }
 
   MicroBenchmarkController micro_benchmark_controller_;
 
   void OnCommitForSwapPromises();
 
   void RecordGpuRasterizationHistogram();
 
  private:
+  friend class LayerTreeHostSerializationTest;
+
   void InitializeProxy(
       scoped_ptr<Proxy> proxy,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
 
   bool DoUpdateLayers(Layer* root_layer);
   void UpdateHudLayer();
 
   bool AnimateLayersRecursive(Layer* current, base::TimeTicks time);
 
   bool IsSingleThreaded() const;
@@ skipping 103 matching lines @@
 
   uint32_t surface_id_namespace_;
   uint32_t next_surface_sequence_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_