Add preliminary support for hw-accelerated tile rasterization.

cc/resources/raster_worker_pool.h

Index: cc/resources/raster_worker_pool.h
diff --git a/cc/resources/raster_worker_pool.h b/cc/resources/raster_worker_pool.h
index fac2fd845ce81db11136a986f0437db89f6e8867..5db134cdeee0e494a58d35b48b5b575b0ede1bfb 100644
--- a/cc/resources/raster_worker_pool.h
+++ b/cc/resources/raster_worker_pool.h
@@ -36,6 +36,7 @@ class CC_EXPORT RasterWorkerPoolTask
                                  void* buffer,
                                  gfx::Size size,
                                  int stride) = 0;
+  virtual void RunOnOriginThread() = 0;
   virtual void CompleteOnOriginThread() = 0;
 
   void DidRun(bool was_canceled);
@@ -144,8 +145,10 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
 
       typedef std::vector<scoped_refptr<internal::RasterWorkerPoolTask> >
           TaskVector;
-      TaskVector tasks_;
       typedef base::hash_set<internal::RasterWorkerPoolTask*> TaskSet;
+      TaskVector origin_thread_tasks_;

[reveman, 2013/12/17 00:28:48]

Maybe we should put all tasks in |tasks_| for now and pull them out and run them
on the origin thread more as an implementation detail of the RasterWorkerPool.
Wdyt?

[alokp, 2013/12/17 22:12:15]

Done.

+      // Worker thread tasks.
+      TaskVector tasks_;
       TaskSet tasks_required_for_activation_;
     };
 
@@ -162,9 +165,13 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
     friend class RasterWorkerPool;
     friend class RasterWorkerPoolTest;
 
-    explicit RasterTask(internal::RasterWorkerPoolTask* internal);
+    explicit RasterTask(internal::RasterWorkerPoolTask* internal,
+                        bool must_run_on_origin_thread);
 
     scoped_refptr<internal::RasterWorkerPoolTask> internal_;
+    // True if this task must be run on origin thread,
+    // not on a worker thread.
+    bool must_run_on_origin_thread_;

[reveman, 2013/12/17 00:28:48]

Why must_run_on_origin_thread here but use_gpu_rasterization when passed to
CreateRasterTask? Also, could this be a internal::RasterWorkerPoolTask member
instead?

[alokp, 2013/12/17 22:12:15]

Done.

   };
 
   virtual ~RasterWorkerPool();
@@ -189,7 +196,7 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
   virtual ResourceFormat GetResourceFormat() const = 0;
 
   // TODO(vmpstr): Figure out an elegant way to not pass this many parameters.
-  static RasterTask CreateRasterTask(
+  RasterTask CreateRasterTask(
       const Resource* resource,
       PicturePileImpl* picture_pile,
       gfx::Rect content_rect,
@@ -199,6 +206,7 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
       int layer_id,
       const void* tile_id,
       int source_frame_number,
+      bool use_gpu_rasterization,
       RenderingStatsInstrumentation* rendering_stats,
       const RasterTask::Reply& reply,
       Task::Set* dependencies);
@@ -218,17 +226,21 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
   typedef base::hash_map<TaskMapKey,
                          scoped_refptr<internal::WorkerPoolTask> > TaskMap;
 
-  RasterWorkerPool(ResourceProvider* resource_provider, size_t num_threads);
+  RasterWorkerPool(ResourceProvider* resource_provider,
+                   ContextProvider* context_provider,
+                   size_t num_threads);
 
   virtual void OnRasterTasksFinished() = 0;
   virtual void OnRasterTasksRequiredForActivationFinished() = 0;
 
+  void CompleteOriginThreadTasks(RasterTask::Queue* queue);

[reveman, 2013/12/17 00:28:48]

Do you have to pass a RasterTask::Queue* to this function? Could you instead
pass a TaskVector?

[alokp, 2013/12/17 22:12:15]

Done.

   void SetRasterTasks(RasterTask::Queue* queue);
   bool IsRasterTaskRequiredForActivation(
       internal::RasterWorkerPoolTask* task) const;
 
   RasterWorkerPoolClient* client() const { return client_; }
   ResourceProvider* resource_provider() const { return resource_provider_; }
+  ContextProvider* context_provider() const { return context_provider_; }
   const RasterTaskVector& raster_tasks() const { return raster_tasks_; }
   const RasterTaskSet& raster_tasks_required_for_activation() const {
     return raster_tasks_required_for_activation_;
@@ -268,6 +280,7 @@ class CC_EXPORT RasterWorkerPool : public WorkerPool {
 
   RasterWorkerPoolClient* client_;
   ResourceProvider* resource_provider_;
+  ContextProvider* context_provider_;
   RasterTask::Queue::TaskVector raster_tasks_;
   RasterTask::Queue::TaskSet raster_tasks_required_for_activation_;