cc/blimp: Add synchronization for scroll/scale state.

cc/trees/layer_tree_host_in_process.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_IN_PROCESS_H_
 #define CC_TREES_LAYER_TREE_HOST_IN_PROCESS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 49 matching lines @@
 class LayerTreeHostSingleThreadClient;
 class LayerTreeMutator;
 class PropertyTrees;
 class Region;
 class RemoteProtoChannel;
 class RenderingStatsInstrumentation;
 class ResourceProvider;
 class ResourceUpdateQueue;
 class TaskGraphRunner;
 struct PendingPageScaleAnimation;
+struct ReflectedMainFrameState;
 struct RenderingStats;
 struct ScrollAndScaleSet;
 
 namespace proto {
 class LayerTreeHost;
 }
 
 class CC_EXPORT LayerTreeHostInProcess : public LayerTreeHost {
  public:
   // TODO(sad): InitParams should be a movable type so that it can be
@@ skipping 100 matching lines @@
   void DidLoseCompositorFrameSink();
   void DidCommitAndDrawFrame() { client_->DidCommitAndDrawFrame(); }
   void DidReceiveCompositorFrameAck() {
     client_->DidReceiveCompositorFrameAck();
   }
   bool UpdateLayers();
   // Called when the compositor completed page scale animation.
   void DidCompletePageScaleAnimation();
   void ApplyScrollAndScale(ScrollAndScaleSet* info);
 
+  void SetReflectedMainFrameState(
+      std::unique_ptr<ReflectedMainFrameState> reflected_main_frame_state);
+  const ReflectedMainFrameState* reflected_main_frame_state_for_testing()
+      const {
+    return reflected_main_frame_state_.get();
+  }
+
   LayerTreeHostClient* client() { return client_; }
 
   bool gpu_rasterization_histogram_recorded() const {
     return gpu_rasterization_histogram_recorded_;
   }
 
   void CollectRenderingStats(RenderingStats* stats) const;
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation() const {
     return rendering_stats_instrumentation_.get();
@@ skipping 142 matching lines @@
 
   TaskGraphRunner* task_graph_runner_;
 
   ImageSerializationProcessor* image_serialization_processor_;
   std::unique_ptr<EnginePictureCache> engine_picture_cache_;
   std::unique_ptr<ClientPictureCache> client_picture_cache_;
 
   SurfaceSequenceGenerator surface_sequence_generator_;
   uint32_t num_consecutive_frames_suitable_for_gpu_ = 0;
 
+  // The state that was expected to be reflected from the main thread during
+  // BeginMainFrame, but could not be done. The client provides these deltas
+  // to use during the commit instead of applying them at that point because
+  // its necessary for these deltas to be applied *after* PropertyTrees are
+  // built/updated on the main thread.
+  // TODO(khushalsagar): Investigate removing this after SPV2, since then we
+  // should get these PropertyTrees directly from blink?
+  std::unique_ptr<ReflectedMainFrameState> reflected_main_frame_state_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostInProcess);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IN_PROCESS_H_