cc: Add TaskGraphRunner sub-namespaces with task concurrency limits.

cc/resources/pixel_buffer_tile_task_worker_pool.cc

Index: cc/resources/pixel_buffer_tile_task_worker_pool.cc
diff --git a/cc/resources/pixel_buffer_tile_task_worker_pool.cc b/cc/resources/pixel_buffer_tile_task_worker_pool.cc
index f74e066e1a33e058c510199580ad5979dde9abdc..70712ce43c53b92508df99b1244e5f20ee75467d 100644
--- a/cc/resources/pixel_buffer_tile_task_worker_pool.cc
+++ b/cc/resources/pixel_buffer_tile_task_worker_pool.cc
@@ -558,7 +558,8 @@ void PixelBufferTileTaskWorkerPool::ScheduleMoreTasks() {
            state.type == RasterTaskState::SCHEDULED);
     state.type = RasterTaskState::SCHEDULED;
 
-    InsertNodesForRasterTask(&graph_, task, task->dependencies(), priority++);
+    InsertNodesForRasterTask(&graph_, task, task->dependencies(), priority++,
+                             kDefaultSubNamespace, kDefaultMaxConcurrentTasks);
 
     ++scheduled_raster_task_count;
     for (TaskSet task_set = 0; task_set < kNumberOfTaskSets; ++task_set) {
@@ -589,7 +590,8 @@ void PixelBufferTileTaskWorkerPool::ScheduleMoreTasks() {
       task_set_finished_tasks_pending_[task_set] = true;
       InsertNodeForTask(&graph_, new_task_set_finished_tasks[task_set].get(),
                         kTaskSetFinishedTaskPriorityBase + task_set,
-                        scheduled_task_counts[task_set]);
+                        scheduled_task_counts[task_set], kDefaultSubNamespace,
+                        kDefaultMaxConcurrentTasks);
       for (RasterTaskVector::ContainerType::const_iterator it =
                tasks[task_set].container().begin();
            it != tasks[task_set].container().end(); ++it) {