cc: Rework how picture layer tiling set gets into raster queues.

cc/resources/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_RESOURCES_PICTURE_LAYER_TILING_SET_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_SET_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 24 matching lines @@
     BETWEEN_HIGH_AND_LOW_RES,
     LOW_RES,
     LOWER_THAN_LOW_RES
   };
   struct TilingRange {
     TilingRange(size_t start, size_t end) : start(start), end(end) {}
 
     size_t start;
     size_t end;
   };
+  struct Pair {
+    PictureLayerTilingSet* active = nullptr;
+    PictureLayerTilingSet* pending = nullptr;
+  };
 
   static scoped_ptr<PictureLayerTilingSet> Create(
       PictureLayerTilingClient* client,
       size_t max_tiles_for_interest_area,
       float skewport_target_time_in_seconds,
       int skewport_extrapolation_limit_in_content);
 
   ~PictureLayerTilingSet();
 
   const PictureLayerTilingClient* client() const { return client_; }
@@ skipping 52 matching lines @@
 
   // Update the rects and priorities for tiles based on the given information.
   bool UpdateTilePriorities(const gfx::Rect& required_rect_in_layer_space,
                             float ideal_contents_scale,
                             double current_frame_time_in_seconds,
                             const Occlusion& occlusion_in_layer_space,
                             bool can_require_tiles_for_activation);
 
   void GetAllTilesForTracing(std::set<const Tile*>* tiles) const;
 
+  bool HasValidTilePriorities() const;
+
   // 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 CoverageIterator {
    public:
     CoverageIterator(const PictureLayerTilingSet* set,
       float contents_scale,
       const gfx::Rect& content_rect,
@@ skipping 52 matching lines @@
   const int skewport_extrapolation_limit_in_content_pixels_;
   PictureLayerTilingClient* client_;
 
   friend class Iterator;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingSet);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_SET_H_