cc: Update picture pile on tiles to prevent memory leak

cc/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_PICTURE_LAYER_TILING_SET_H_
 #define CC_PICTURE_LAYER_TILING_SET_H_
 
 #include "cc/picture_layer_tiling.h"
 #include "cc/region.h"
 #include "cc/scoped_ptr_vector.h"
@@ skipping 35 matching lines @@
 
   void UpdateTilePriorities(
       WhichTree tree,
       const gfx::Size& device_viewport,
       float layer_content_scale_x,
       float layer_content_scale_y,
       const gfx::Transform& last_screen_transform,
       const gfx::Transform& current_screen_transform,
       double time_delta);
 
-  // Copies the src_tree priority into the dst_tree priority for all tiles.
-  // The src_tree priority is reset to the lowest priority possible.
-  void MoveTilePriorities(WhichTree src_tree, WhichTree dst_tree);
+  void DidBecomeActive();
 
   // For a given rect, iterates through tiles that can fill it.  If no
   // set of tiles with resources can fill the rect, then it will iterate
   // through null tiles with valid geometry_rect() until the rect is full.
   // If all tiles have resources, the union of all geometry_rects will
   // exactly fill rect with no overlap.
   class CC_EXPORT Iterator {
    public:
     Iterator(
       const PictureLayerTilingSet* set,
@@ skipping 38 matching lines @@
   gfx::Size layer_bounds_;
   ScopedPtrVector<PictureLayerTiling> tilings_;
   Region invalidation_;
 
   friend class Iterator;
 };
 
 }  // namespace cc
 
 #endif  // CC_PICTURE_LAYER_TILING_SET_H_