cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/raster/one_copy_tile_task_worker_pool.cc

Index: cc/raster/one_copy_tile_task_worker_pool.cc
diff --git a/cc/raster/one_copy_tile_task_worker_pool.cc b/cc/raster/one_copy_tile_task_worker_pool.cc
index 47e4c01c5a6ddb37f1513c1311f4cb402d7e97ac..5225474afcbd5d49b925434de34dac4e5390902c 100644
--- a/cc/raster/one_copy_tile_task_worker_pool.cc
+++ b/cc/raster/one_copy_tile_task_worker_pool.cc
@@ -128,8 +128,6 @@ void OneCopyTileTaskWorkerPool::Shutdown() {
 void OneCopyTileTaskWorkerPool::ScheduleTasks(TaskGraph* graph) {
   TRACE_EVENT0("cc", "OneCopyTileTaskWorkerPool::ScheduleTasks");
 
-  ScheduleTasksOnOriginThread(this, graph);
-
   // Barrier to sync any new resources to the worker context.
   resource_provider_->output_surface()
       ->context_provider()
@@ -139,21 +137,11 @@ void OneCopyTileTaskWorkerPool::ScheduleTasks(TaskGraph* graph) {
   task_graph_runner_->ScheduleTasks(namespace_token_, graph);
 }
 
-void OneCopyTileTaskWorkerPool::CheckForCompletedTasks() {
+void OneCopyTileTaskWorkerPool::CollectCompletedTasks(
+    Task::Vector* completed_tasks) {
   TRACE_EVENT0("cc", "OneCopyTileTaskWorkerPool::CheckForCompletedTasks");
 
-  task_graph_runner_->CollectCompletedTasks(namespace_token_,
-                                            &completed_tasks_);
-
-  for (Task::Vector::const_iterator it = completed_tasks_.begin();
-       it != completed_tasks_.end(); ++it) {
-    TileTask* task = static_cast<TileTask*>(it->get());
-
-    task->WillComplete();
-    task->CompleteOnOriginThread(this);
-    task->DidComplete();
-  }
-  completed_tasks_.clear();
+  task_graph_runner_->CollectCompletedTasks(namespace_token_, completed_tasks);
 }
 
 ResourceFormat OneCopyTileTaskWorkerPool::GetResourceFormat(
@@ -172,6 +160,10 @@ bool OneCopyTileTaskWorkerPool::GetResourceRequiresSwizzle(
   return ResourceFormatRequiresSwizzle(GetResourceFormat(must_support_alpha));
 }
 
+TileTaskClient* OneCopyTileTaskWorkerPool::AsTileTaskClient() {
+  return this;
+}
+
 std::unique_ptr<RasterBuffer> OneCopyTileTaskWorkerPool::AcquireBufferForRaster(
     const Resource* resource,
     uint64_t resource_content_id,
@@ -270,6 +262,8 @@ void OneCopyTileTaskWorkerPool::CopyOnWorkerThread(
     const RasterSource* raster_source,
     uint64_t previous_content_id,
     uint64_t new_content_id) {
+  DCHECK(resource->size().width() && resource->size().height());
+
   ContextProvider* context_provider =
       resource_provider_->output_surface()->worker_context_provider();
   DCHECK(context_provider);