cc: Prevent recursion in *TileTaskWorkerPool methods.

cc/resources/tile_manager.h

Index: cc/resources/tile_manager.h
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index a5005bf7f3cce2da6d11082e5567633af2468a1a..fa213858d212f4424d2d0e66a191bdc378e8d79b 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -243,6 +243,7 @@ class CC_EXPORT TileManager : public TileTaskRunnerClient,
   bool IsReadyToDraw() const;
   void CheckIfReadyToActivate();
   void CheckIfReadyToDraw();
+  void CheckIfMoreTilesNeedPrepare();
 
   TileManagerClient* client_;
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
@@ -281,6 +282,7 @@ class CC_EXPORT TileManager : public TileTaskRunnerClient,
 
   UniqueNotifier ready_to_activate_check_notifier_;
   UniqueNotifier ready_to_draw_check_notifier_;
+  UniqueNotifier more_tiles_need_prepare_check_notifier_;
 
   RasterTilePriorityQueue raster_priority_queue_;
   EvictionTilePriorityQueue eviction_priority_queue_;