cc: Optimize decode scheduling for checker-images.

cc/tiles/tile.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_TILE_H_
 #define CC_TILES_TILE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 95 matching lines @@
 
   bool HasRasterTask() const { return !!raster_task_.get(); }
 
   void set_solid_color_analysis_performed(bool performed) {
     is_solid_color_analysis_performed_ = performed;
   }
   bool is_solid_color_analysis_performed() const {
     return is_solid_color_analysis_performed_;
   }
 
+  bool raster_task_scheduled_with_checker_images() const {

[vmpstr, 2017/03/29 19:11:45]

Add a setter as well. I want to remove the friend TileManager on the tile
eventually.

This needs a comment: unlike "solid color analysis performed" which mean we've
done the analysis, this could be interpreted that the raster task is _currently_
scheduled, vs raster task has _ever_ been scheduled. Also, remove the
"raster_task" part here.

This also gives me an interesting thought: if we checker an image, can it be the
case that the tile afterwards is solid color? I'm not sure it's worth looking at
this, but something to consider in the future if we want to save some memory
while we're decoding the image.

[Khushal, 2017/03/29 22:10:20]

Its definitely going to be possible and something to optimize.

[Khushal, 2017/03/31 04:31:00]

Done.

+    return raster_task_scheduled_with_checker_images_;
+  }
+
   const PictureLayerTiling* tiling() const { return tiling_; }
   void set_tiling(const PictureLayerTiling* tiling) { tiling_ = tiling; }
 
  private:
   friend class TileManager;
   friend class FakeTileManager;
   friend class FakePictureLayerImpl;
 
   // Methods called by by tile manager.
   Tile(TileManager* tile_manager,
@@ skipping 21 matching lines @@
 
   Id id_;
 
   // The rect bounding the changes in this Tile vs the previous tile it
   // replaced.
   gfx::Rect invalidated_content_rect_;
   // The |id_| of the Tile that was invalidated and replaced by this tile.
   Id invalidated_id_;
 
   unsigned scheduled_priority_;
+  bool raster_task_scheduled_with_checker_images_ = false;
   scoped_refptr<TileTask> raster_task_;
 
   DISALLOW_COPY_AND_ASSIGN(Tile);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_TILE_H_