cc: Give non-drawing layers that are rasterized a lower priority.

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 108 matching lines @@
   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;
   }
   void set_can_require_tiles_for_activation(bool can_require_tiles) {
     can_require_tiles_for_activation_ = can_require_tiles;
   }
+  bool can_require_tiles_for_activation() const {
+    return can_require_tiles_for_activation_;
+  }
 
   const scoped_refptr<RasterSource>& raster_source() const {
     return raster_source_;
   }
   gfx::Size tiling_size() const { return tiling_data_.tiling_size(); }
   gfx::Rect live_tiles_rect() const { return live_tiles_rect_; }
   gfx::Size tile_size() const { return tiling_data_.max_texture_size(); }
   // PictureLayerTilingSet uses the scale component of the raster transform
   // as the key for indexing and sorting. In theory we can have multiple
   // tilings with the same scale but different translation, but currently
@@ skipping 251 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_