cc: Optimize decode scheduling for checker-images.

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 90 matching lines @@
 
   void SetRasterSourceAndResize(scoped_refptr<RasterSource> raster_source);
   void Invalidate(const Region& layer_invalidation);
   void CreateMissingTilesInLiveTilesRect();
   void TakeTilesAndPropertiesFrom(PictureLayerTiling* pending_twin,
                                   const Region& layer_invalidation);
 
   bool IsTileRequiredForActivation(const Tile* tile) const;
   bool IsTileRequiredForDraw(const Tile* tile) const;
 
+  // Returns true if the tile should be processed for decoding images skipped
+  // during rasterization.
+  bool ShouldDecodeCheckeredImagesForTile(const Tile* tile) const;
+
   void set_resolution(TileResolution resolution) {
     resolution_ = resolution;
     may_contain_low_resolution_tiles_ |= resolution == LOW_RESOLUTION;
   }
   TileResolution resolution() const { return resolution_; }
   bool may_contain_low_resolution_tiles() const {
     return may_contain_low_resolution_tiles_;
   }
   void reset_may_contain_low_resolution_tiles() {
     may_contain_low_resolution_tiles_ = false;
@@ skipping 263 matching lines @@
   bool has_eventually_rect_tiles_ = false;
   bool all_tiles_done_ = true;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTiling);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_PICTURE_LAYER_TILING_H_