cc: Remove some unnecessary const scoped_refptr&.

cc/tiles/picture_layer_tiling_set.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_SET_H_
 #define CC_TILES_PICTURE_LAYER_TILING_SET_H_
 
 #include <stddef.h>
 
 #include <set>
@@ skipping 55 matching lines @@
 
   // This function is called on the sync tree during commit.
   void UpdateTilingsToCurrentRasterSourceForCommit(
       scoped_refptr<DisplayListRasterSource> raster_source,
       const Region& layer_invalidation,
       float minimum_contents_scale,
       float maximum_contents_scale);
 
   // This function is called on the sync tree right after commit.
   void UpdateRasterSourceDueToLCDChange(
-      const scoped_refptr<DisplayListRasterSource>& raster_source,
+      scoped_refptr<DisplayListRasterSource> raster_source,
       const Region& layer_invalidation);
 
   PictureLayerTiling* AddTiling(
       float contents_scale,
       scoped_refptr<DisplayListRasterSource> raster_source);
   size_t num_tilings() const { return tilings_.size(); }
   int NumHighResTilings() const;
   PictureLayerTiling* tiling_at(size_t idx) { return tilings_[idx].get(); }
   const PictureLayerTiling* tiling_at(size_t idx) const {
     return tilings_[idx].get();
@@ skipping 89 matching lines @@
  private:
   explicit PictureLayerTilingSet(
       WhichTree tree,
       PictureLayerTilingClient* client,
       size_t tiling_interest_area_padding,
       float skewport_target_time_in_seconds,
       int skewport_extrapolation_limit_in_content_pixels);
 
   void CopyTilingsAndPropertiesFromPendingTwin(
       const PictureLayerTilingSet* pending_twin_set,
-      const scoped_refptr<DisplayListRasterSource>& raster_source,
+      scoped_refptr<DisplayListRasterSource> raster_source,
       const Region& layer_invalidation);
 
   // Remove one tiling.
   void Remove(PictureLayerTiling* tiling);
   void VerifyTilings(const PictureLayerTilingSet* pending_twin_set) const;
 
   std::vector<scoped_ptr<PictureLayerTiling>> tilings_;
 
   const size_t tiling_interest_area_padding_;
   const float skewport_target_time_in_seconds_;
   const int skewport_extrapolation_limit_in_content_pixels_;
   WhichTree tree_;
   PictureLayerTilingClient* client_;
 
   friend class Iterator;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingSet);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_PICTURE_LAYER_TILING_SET_H_