cc: Partial tile update for one-copy raster.

cc/tiles/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_TILES_PICTURE_LAYER_TILING_H_
 #define CC_TILES_PICTURE_LAYER_TILING_H_
 
 #include <map>
 #include <utility>
 #include <vector>
@@ skipping 258 matching lines @@
   PictureLayerTiling(WhichTree tree,
                      float contents_scale,
                      scoped_refptr<RasterSource> raster_source,
                      PictureLayerTilingClient* client,
                      float tiling_interest_area_viewport_multiplier,
                      float skewport_target_time_in_seconds,
                      int skewport_extrapolation_limit_in_content_pixels);
   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);

[reveman, 2015/05/28 05:07:25]

adding an 'id' output param seems a bit too specific for the exact usage of this
patch. I think it would be nicer to add an alternative TakeTileAt function that
allows you to get the id when needed and the existing RemoveTileAt function can
simply be implemented on top of it.

[danakj, 2015/05/28 18:54:47]

I think we're making perfect the enemy of the good.

Done. I didn't make RemoveTileAt use TakeTileAt. That would just be more pointer
moving around for no use.

   bool TilingMatchesTileIndices(const PictureLayerTiling* twin) const;
 
   // 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;
 
@@ skipping 105 matching lines @@
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_PICTURE_LAYER_TILING_H_