cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/raster/gpu_tile_task_worker_pool.h

Index: cc/raster/gpu_tile_task_worker_pool.h
diff --git a/cc/raster/gpu_tile_task_worker_pool.h b/cc/raster/gpu_tile_task_worker_pool.h
index 6943a271c0ef1d50fc7aba9d21d3260a7b7eabcd..6e68214d3d5a4190892f3ea07d18030b3cc1ff12 100644
--- a/cc/raster/gpu_tile_task_worker_pool.h
+++ b/cc/raster/gpu_tile_task_worker_pool.h
@@ -36,9 +36,10 @@ class CC_EXPORT GpuTileTaskWorkerPool : public TileTaskWorkerPool,
   // Overridden from TileTaskRunner:
   void Shutdown() override;
   void ScheduleTasks(TaskGraph* graph) override;
-  void CheckForCompletedTasks() override;
+  void CollectCompletedTasks(Task::Vector* completed_tasks) override;
   ResourceFormat GetResourceFormat(bool must_support_alpha) const override;
   bool GetResourceRequiresSwizzle(bool must_support_alpha) const override;
+  TileTaskClient* AsTileTaskClient() override;
 
   // Overridden from TileTaskClient:
   std::unique_ptr<RasterBuffer> AcquireBufferForRaster(
@@ -55,15 +56,11 @@ class CC_EXPORT GpuTileTaskWorkerPool : public TileTaskWorkerPool,
                         bool use_distance_field_text,
                         int gpu_rasterization_msaa_sample_count);
 
-  void CompleteTasks(const Task::Vector& tasks);
-
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   TaskGraphRunner* task_graph_runner_;
   const NamespaceToken namespace_token_;
   std::unique_ptr<GpuRasterizer> rasterizer_;
 
-  Task::Vector completed_tasks_;
-
   DISALLOW_COPY_AND_ASSIGN(GpuTileTaskWorkerPool);
 };