Add preliminary support for hw-accelerated tile rasterization.

cc/resources/pixel_buffer_raster_worker_pool.h

Index: cc/resources/pixel_buffer_raster_worker_pool.h
diff --git a/cc/resources/pixel_buffer_raster_worker_pool.h b/cc/resources/pixel_buffer_raster_worker_pool.h
index 0444ed6892eb52c0673d97387a331f6aa5be74e0..4a5a191d946a6fbbdbc4e5a89086ef2bc05936fa 100644
--- a/cc/resources/pixel_buffer_raster_worker_pool.h
+++ b/cc/resources/pixel_buffer_raster_worker_pool.h
@@ -20,27 +20,30 @@ class CC_EXPORT PixelBufferRasterWorkerPool : public RasterWorkerPool {
 
   static scoped_ptr<RasterWorkerPool> Create(
       ResourceProvider* resource_provider,
+      ContextProvider* context_provider,
       size_t num_threads,
       size_t max_transfer_buffer_usage_bytes) {
     return make_scoped_ptr<RasterWorkerPool>(
         new PixelBufferRasterWorkerPool(resource_provider,
+                                        context_provider,
                                         num_threads,
                                         max_transfer_buffer_usage_bytes));
   }
 
   // Overridden from WorkerPool:
   virtual void Shutdown() OVERRIDE;
-  virtual void CheckForCompletedTasks() OVERRIDE;
 
   // Overridden from RasterWorkerPool:
   virtual void ScheduleTasks(RasterTask::Queue* queue) OVERRIDE;
   virtual GLenum GetResourceTarget() const OVERRIDE;
   virtual ResourceFormat GetResourceFormat() const OVERRIDE;
+  virtual void CheckForCompletedTasks() OVERRIDE;
   virtual void OnRasterTasksFinished() OVERRIDE;
   virtual void OnRasterTasksRequiredForActivationFinished() OVERRIDE;
 
  private:
   PixelBufferRasterWorkerPool(ResourceProvider* resource_provider,
+                              ContextProvider* context_provider,
                               size_t num_threads,
                               size_t max_transfer_buffer_usage_bytes);