WIP GPU scheduler + delayed activation / tile draw

cc/tiles/tile_manager.h

Index: cc/tiles/tile_manager.h
diff --git a/cc/tiles/tile_manager.h b/cc/tiles/tile_manager.h
index 1136708ebde1b4d5a1cfc7c145d4669391db74c0..f0cc6b319c5891fdb337a06e36982b2c60cf06bd 100644
--- a/cc/tiles/tile_manager.h
+++ b/cc/tiles/tile_manager.h
@@ -262,6 +262,7 @@ class CC_EXPORT TileManager {
     std::vector<PrioritizedTile> tiles_to_process_for_images;
   };
 
+  void AcquireResourcesForTile(Tile* tile);
   void FreeResourcesForTile(Tile* tile);
   void FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(Tile* tile);
   scoped_refptr<TileTask> CreateRasterTask(
@@ -293,6 +294,14 @@ class CC_EXPORT TileManager {
   void DidFinishRunningTileTasksRequiredForDraw();
   void DidFinishRunningAllTileTasks();
 
+  void OnRequiredForActivationTilesReadyToDraw();
+  void OnRequiredForDrawTilesReadyToDraw();
+
+  void CheckRequiredForActivationTilesReadyToDraw();
+  void CheckRequiredForDrawTilesReadyToDraw();
+
+  void OnTileReadyToDraw(Tile* tile);
+
   scoped_refptr<TileTask> CreateTaskSetFinishedTask(
       void (TileManager::*callback)());
   PrioritizedWorkToSchedule AssignGpuMemoryToTiles();
@@ -329,6 +338,9 @@ class CC_EXPORT TileManager {
 
   TaskGraph graph_;
 
+  std::vector<Tile*> pending_required_for_activation_tiles_;
+  std::vector<Tile*> pending_required_for_draw_tiles_;
+
   UniqueNotifier more_tiles_need_prepare_check_notifier_;
 
   Signals signals_;
@@ -345,6 +357,8 @@ class CC_EXPORT TileManager {
 
   base::WeakPtrFactory<TileManager> task_set_finished_weak_ptr_factory_;
 
+  base::WeakPtrFactory<TileManager> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };