cc: Gather and lock/unlock SkDiscardablePixelRefs instead of skia::LazyPixelRefs.

cc/resources/picture_pile_impl.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_RESOURCES_PICTURE_PILE_IMPL_H_
 #define CC_RESOURCES_PICTURE_PILE_IMPL_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 69 matching lines @@
                      Analysis* analysis,
                      RenderingStatsInstrumentation* stats_instrumentation);
 
   class CC_EXPORT PixelRefIterator {
    public:
     PixelRefIterator(gfx::Rect content_rect,
                      float contents_scale,
                      const PicturePileImpl* picture_pile);
     ~PixelRefIterator();
 
-    skia::LazyPixelRef* operator->() const { return *pixel_ref_iterator_; }
-    skia::LazyPixelRef* operator*() const { return *pixel_ref_iterator_; }
+    SkPixelRef* operator->() const { return *pixel_ref_iterator_; }
+    SkPixelRef* operator*() const { return *pixel_ref_iterator_; }
     PixelRefIterator& operator++();
     operator bool() const { return pixel_ref_iterator_; }
 
    private:
     void AdvanceToTilePictureWithPixelRefs();
 
     const PicturePileImpl* picture_pile_;
     gfx::Rect layer_rect_;
     TilingData::Iterator tile_iterator_;
     Picture::PixelRefIterator pixel_ref_iterator_;
@@ skipping 45 matching lines @@
   // instance.  This member variable must be last so that other member
   // variables have already been initialized and can be clonable.
   const ClonesForDrawing clones_for_drawing_;
 
   DISALLOW_COPY_AND_ASSIGN(PicturePileImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_PILE_IMPL_H_