cc: Separate the priority from the tile and put in new PrioritizedTile

cc/resources/tiling_set_eviction_queue.h

 // Copyright 2014 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_TILING_SET_EVICTION_QUEUE_H_
 #define CC_RESOURCES_TILING_SET_EVICTION_QUEUE_H_
 
 #include <vector>
 
 #include "cc/base/cc_export.h"
 #include "cc/resources/picture_layer_tiling_set.h"
+#include "cc/resources/prioritized_tile.h"
 
 namespace cc {
 
 // This eviction queue returned tiles from all tilings in a tiling set in
 // the order in which the tiles should be evicted. It can be thought of as the
 // following:
 //  for all phases:
 //    for all ordered tilings:
 //      yield the next tile for the given phase from the given tiling
 //
@@ skipping 38 matching lines @@
 // higher of the two trees, we might visit a tile that should actually be
 // returned by its twin. In those situations, the tiles are not returned. That
 // is, since the twin has higher priority, it should return it when it gets to
 // it. This ensures that we don't block raster because we've returned a tile
 // with low priority on one tree, but high combined priority.
 class CC_EXPORT TilingSetEvictionQueue {
  public:
   explicit TilingSetEvictionQueue(PictureLayerTilingSet* tiling_set);
   ~TilingSetEvictionQueue();
 
-  Tile* Top();
-  const Tile* Top() const;
+  const PrioritizedTile& Top() const;
   void Pop();
   bool IsEmpty() const;
 
  private:
   enum Phase {
     EVENTUALLY_RECT,
     SOON_BORDER_RECT,
     SKEWPORT_RECT,
     PENDING_VISIBLE_RECT,
     PENDING_VISIBLE_RECT_REQUIRED_FOR_ACTIVATION,
     VISIBLE_RECT_OCCLUDED,
     VISIBLE_RECT_UNOCCLUDED,
     VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_OCCLUDED,
     VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED
   };
 
   void GenerateTilingOrder(PictureLayerTilingSet* tiling_set);
 
   // Helper base class for individual region iterators.
   class EvictionRectIterator {
    public:
     EvictionRectIterator();
     EvictionRectIterator(std::vector<PictureLayerTiling*>* tilings,
                          WhichTree tree,
                          bool skip_pending_visible_rect);
 
-    bool done() const { return !tile_; }
-    Tile* operator*() const { return tile_; }
+    bool done() const { return prioritized_tile_.tile() == nullptr; }
+    const PrioritizedTile& operator*() const { return prioritized_tile_; }
 
    protected:
     ~EvictionRectIterator() = default;
 
     template <typename TilingIteratorType>
     bool AdvanceToNextTile(TilingIteratorType* iterator);
     template <typename TilingIteratorType>
     bool GetFirstTileAndCheckIfValid(TilingIteratorType* iterator);
 
-    Tile* tile_;
+    PrioritizedTile prioritized_tile_;
     std::vector<PictureLayerTiling*>* tilings_;
     WhichTree tree_;
     bool skip_pending_visible_rect_;
     size_t tiling_index_;
   };
 
   class PendingVisibleTilingIterator : public EvictionRectIterator {
    public:
     PendingVisibleTilingIterator() = default;
     PendingVisibleTilingIterator(std::vector<PictureLayerTiling*>* tilings,
                                  WhichTree tree,
                                  bool return_required_for_activation_tiles);
 
     PendingVisibleTilingIterator& operator++();
 
    private:
-    bool TileMatchesRequiredFlags(const Tile* tile) const;
+    bool TileMatchesRequiredFlags(const PrioritizedTile& tile) const;
 
     TilingData::DifferenceIterator iterator_;
     bool return_required_for_activation_tiles_;
   };
 
   class VisibleTilingIterator : public EvictionRectIterator {
    public:
     VisibleTilingIterator() = default;
     VisibleTilingIterator(std::vector<PictureLayerTiling*>* tilings,
                           WhichTree tree,
                           bool return_occluded_tiles,
                           bool return_required_for_activation_tiles);
 
     VisibleTilingIterator& operator++();
 
    private:
-    bool TileMatchesRequiredFlags(const Tile* tile) const;
+    bool TileMatchesRequiredFlags(const PrioritizedTile& tile) const;
 
     TilingData::Iterator iterator_;
     bool return_occluded_tiles_;
     bool return_required_for_activation_tiles_;
   };
 
   class SkewportTilingIterator : public EvictionRectIterator {
    public:
     SkewportTilingIterator() = default;
     SkewportTilingIterator(std::vector<PictureLayerTiling*>* tilings,
@@ skipping 26 matching lines @@
     EventuallyTilingIterator& operator++();
 
    private:
     TilingData::ReverseSpiralDifferenceIterator iterator_;
   };
 
   void AdvancePhase();
 
   WhichTree tree_;
   Phase phase_;
-  Tile* current_tile_;
+  PrioritizedTile current_tile_;
   std::vector<PictureLayerTiling*> tilings_;
 
   EventuallyTilingIterator eventually_iterator_;
   SoonBorderTilingIterator soon_iterator_;
   SkewportTilingIterator skewport_iterator_;
   PendingVisibleTilingIterator pending_visible_iterator_;
   VisibleTilingIterator visible_iterator_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILING_SET_EVICTION_QUEUE_H_