Implement the logic to kick off image decoding jobs for TileManager

cc/tile_manager.h

Index: cc/tile_manager.h
diff --git a/cc/tile_manager.h b/cc/tile_manager.h
index 43c9064125097f9a0c5348d9b6ecaba89d4dbbf6..7f66d284264efcd7fc8a5082a0f27d202f2bc2c1 100644
--- a/cc/tile_manager.h
+++ b/cc/tile_manager.h
@@ -57,6 +57,8 @@ class CC_EXPORT ManagedTileState {
   TileManagerBin bin;
   TileResolution resolution;
   float time_to_needed_in_seconds;
+  bool has_image_decoding_info;
+  std::vector<SkPixelRef*> pending_pixel_refs;
 };
 
 // This class manages tiles, deciding which should get rasterized and which
@@ -96,6 +98,12 @@ class CC_EXPORT TileManager {
       scoped_refptr<PicturePileImpl>,
       RenderingStats*);
   void DidFinishTileInitialization(Tile*, scoped_ptr<ResourcePool::Resource>);
+  bool HasUndecodedImages(Tile*, std::vector<SkPixelRef*>&);
+  void OnImageDecodingTaskCompleted(uint32_t pixel_ref_id);
+  void DispatchOneImageDecodingTask(RasterThread*, SkPixelRef*);
+  void DispatchMoreImageDecodingTasks(std::vector<SkPixelRef*>&);
+  void GetImageInformationForTile(Tile*);
+  RasterThread* GetFreeRasterThread();
 
   TileManagerClient* client_;
   scoped_ptr<ResourcePool> resource_pool_;
@@ -106,6 +114,11 @@ class CC_EXPORT TileManager {
   typedef std::vector<Tile*> TileVector;
   TileVector tiles_;
   TileVector tiles_that_need_to_be_rasterized_;
+  // Tiles that are waiting for image decoding tasks.
+  TileVector tiles_waiting_for_image_decoding_;
+
+  typedef base::hash_map<uint32_t, SkPixelRef*> PixelRefMap;
+  PixelRefMap pending_decode_tasks_;
 
   typedef ScopedPtrVector<RasterThread> RasterThreadVector;
   RasterThreadVector raster_threads_;