Tile Compression

cc/resources/picture_layer_tiling.h

Index: cc/resources/picture_layer_tiling.h
diff --git a/cc/resources/picture_layer_tiling.h b/cc/resources/picture_layer_tiling.h
index daa04851d9c22f8759e283d5fd0d9d048b3f22bb..8b3cf6760ea5b9cb2e6f62141cfe44afc1a77e56 100644
--- a/cc/resources/picture_layer_tiling.h
+++ b/cc/resources/picture_layer_tiling.h
@@ -35,9 +35,9 @@ class CC_EXPORT PictureLayerTilingClient {
  public:
   // Create a tile at the given content_rect (in the contents scale of the
   // tiling) This might return null if the client cannot create such a tile.
-  virtual scoped_refptr<Tile> CreateTile(
-    PictureLayerTiling* tiling,
-    const gfx::Rect& content_rect) = 0;
+  virtual scoped_refptr<Tile> CreateTile(PictureLayerTiling* tiling,
+                                         const gfx::Rect& content_rect,
+                                         int flags) = 0;
   virtual gfx::Size CalculateTileSize(
     const gfx::Size& content_bounds) const = 0;
   // This invalidation region defines the area (if any, it can by null) that
@@ -128,7 +128,8 @@ class CC_EXPORT PictureLayerTiling {
   gfx::Size layer_bounds() const { return layer_bounds_; }
   void UpdateTilesToCurrentRasterSource(RasterSource* raster_source,
                                         const Region& layer_invalidation,
-                                        const gfx::Size& new_layer_bounds);
+                                        const gfx::Size& new_layer_bounds,
+                                        base::TimeTicks frame_time);
   void CreateMissingTilesInLiveTilesRect();
   void RemoveTilesInRegion(const Region& layer_region);
 
@@ -283,8 +284,24 @@ class CC_EXPORT PictureLayerTiling {
   friend class TilingRasterTileIterator;
   friend class TilingSetEvictionQueue;
 
+  class CC_EXPORT TileInvalidationState {
+   public:
+    TileInvalidationState();
+
+    void Invalidate(base::TimeTicks current_frame_time);
+    bool FrequentlyInvalidated() const;
+
+   private:
+    static const int kFrequentInvalidationThreshold;
+
+    base::TimeTicks last_frame_time_;
+    int frame_count_;
+  };
+
   typedef std::pair<int, int> TileMapKey;
   typedef base::hash_map<TileMapKey, scoped_refptr<Tile>> TileMap;
+  typedef base::hash_map<TileMapKey, TileInvalidationState>
+      TileInvalidationStateMap;
 
   PictureLayerTiling(float contents_scale,
                      const gfx::Size& layer_bounds,
@@ -293,7 +310,10 @@ class CC_EXPORT PictureLayerTiling {
   void VerifyLiveTilesRect();
   Tile* CreateTile(int i, int j, const PictureLayerTiling* twin_tiling);
   // Returns true if the Tile existed and was removed from the tiling.
-  bool RemoveTileAt(int i, int j, PictureLayerTiling* recycled_twin);
+  bool RemoveTileAt(int i,
+                    int j,
+                    PictureLayerTiling* recycled_twin,
+                    bool remove_invalidation_state);
 
   // Computes a skewport. The calculation extrapolates the last visible
   // rect and the current visible rect to expand the skewport to where it
@@ -307,10 +327,11 @@ class CC_EXPORT PictureLayerTiling {
   const std::vector<Tile*>* GetEvictionTiles(TreePriority tree_priority,
                                              EvictionCategory category);
 
-  void Invalidate(const Region& layer_region);
+  void Invalidate(const Region& layer_region, base::TimeTicks frame_time);
 
   void DoInvalidate(const Region& layer_region,
-                    bool recreate_invalidated_tiles);
+                    bool recreate_invalidated_tiles,
+                    base::TimeTicks frame_time);
 
   void UpdateTileAndTwinPriority(Tile* tile) const;
   void UpdateTilePriority(Tile* tile) const;
@@ -324,6 +345,7 @@ class CC_EXPORT PictureLayerTiling {
   // Internal data.
   TilingData tiling_data_;
   TileMap tiles_;  // It is not legal to have a NULL tile in the tiles_ map.
+  TileInvalidationStateMap tile_invalidation_states_;
   gfx::Rect live_tiles_rect_;
 
   // State saved for computing velocities based upon finite differences.