cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/raster/zero_copy_tile_task_worker_pool.h

Index: cc/raster/zero_copy_tile_task_worker_pool.h
diff --git a/cc/raster/zero_copy_tile_task_worker_pool.h b/cc/raster/zero_copy_tile_task_worker_pool.h
index d8d99481dd21be59324f327daef82e883aaf21dc..41d6682330dcd4300ecfc737828dbee4c2d9d4c0 100644
--- a/cc/raster/zero_copy_tile_task_worker_pool.h
+++ b/cc/raster/zero_copy_tile_task_worker_pool.h
@@ -40,9 +40,10 @@ class CC_EXPORT ZeroCopyTileTaskWorkerPool : 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(
@@ -68,8 +69,6 @@ class CC_EXPORT ZeroCopyTileTaskWorkerPool : public TileTaskWorkerPool,
 
   ResourceFormat preferred_tile_format_;
 
-  Task::Vector completed_tasks_;
-
   DISALLOW_COPY_AND_ASSIGN(ZeroCopyTileTaskWorkerPool);
 };