cc: Remove and Create the correct tiles when resizing live tiles rect

cc/resources/picture_layer_tiling.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_RESOURCES_PICTURE_LAYER_TILING_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 278 matching lines @@
   friend class TilingRasterTileIterator;
   friend class TilingEvictionTileIterator;
 
   typedef std::pair<int, int> TileMapKey;
   typedef base::hash_map<TileMapKey, scoped_refptr<Tile> > TileMap;
 
   PictureLayerTiling(float contents_scale,
                      const gfx::Size& layer_bounds,
                      PictureLayerTilingClient* client);
   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
+  void VerifyLiveTilesRect();
   Tile* CreateTile(int i, int j, const PictureLayerTiling* twin_tiling);
-  void RemoveTileAt(int i, int j);
+  // Returns true if the Tile existed and was removed from the tiling.
+  bool RemoveTileAt(int i, int j, PictureLayerTiling* recycled_twin);
 
   // Computes a skewport. The calculation extrapolates the last visible
   // rect and the current visible rect to expand the skewport to where it
   // would be in |skewport_target_time| seconds. Note that the skewport
   // is guaranteed to contain the current visible rect.
   gfx::Rect ComputeSkewport(double current_frame_time_in_seconds,
                             const gfx::Rect& visible_rect_in_content_space)
       const;
 
   void UpdateEvictionCacheIfNeeded(TreePriority tree_priority);
@@ skipping 46 matching lines @@
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_