cc: Partial tile update for one-copy raster.

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 76723a348f1c873b346d1fb50aaea5791cc34d5d..8c5e05629592160d2e789216ba6e99faf7f7c9f5 100644
--- a/cc/resources/picture_layer_tiling.h
+++ b/cc/resources/picture_layer_tiling.h
@@ -233,8 +233,9 @@ class CC_EXPORT PictureLayerTiling {
   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
   void VerifyLiveTilesRect(bool is_on_recycle_tree) const;
   Tile* CreateTile(int i, int j);
-  // Returns true if the Tile existed and was removed from the tiling.
-  bool RemoveTileAt(int i, int j);
+  // Returns true if the Tile existed and was removed from the tiling. If true,
+  // and |id| is not null, sets |id| to that of the removed Tile.
+  bool RemoveTileAt(int i, int j, Tile::Id* id);
   bool TilingMatchesTileIndices(const PictureLayerTiling* twin) const;
 
   // Computes a skewport. The calculation extrapolates the last visible