cc: Add tiling raster tile iterators.

cc/resources/picture_layer_tiling.h

Index: cc/resources/picture_layer_tiling.h
diff --git a/cc/resources/picture_layer_tiling.h b/cc/resources/picture_layer_tiling.h
index 407a2ad74d0e4cade0e2becaa889fb776e040c5d..233c54bc1710edab74dd69929c5b98a6597439f3 100644
--- a/cc/resources/picture_layer_tiling.h
+++ b/cc/resources/picture_layer_tiling.h
@@ -45,6 +45,48 @@ class CC_EXPORT PictureLayerTilingClient {
 
 class CC_EXPORT PictureLayerTiling {
  public:
+  class CC_EXPORT TilingRasterTileIterator {
+   public:
+    TilingRasterTileIterator();
+    explicit TilingRasterTileIterator(PictureLayerTiling* tiling);
+    ~TilingRasterTileIterator();
+
+    operator bool() const {
+      return tiling_ && tiling_->RasterTileForPriority(current_index_);
+    }
+    void operator++();
+    Tile* operator*() { return tiling_->RasterTileForPriority(current_index_); }
+
+    bool HasVisibleTiles() const {
+      if (!tiling_)
+        return false;
+      return tiling_->HasVisibleTilesAtOrAfterPriority(current_index_);
+    }
+
+   private:
+    PictureLayerTiling* tiling_;
+    size_t current_index_;
+  };
+
+  class TilingEvictionTileIterator {
+   public:
+    TilingEvictionTileIterator();
+    explicit TilingEvictionTileIterator(PictureLayerTiling* tiling);
+    ~TilingEvictionTileIterator();
+
+    operator bool() const {
+      return tiling_ && tiling_->EvictionTileForPriority(current_index_);
+    }
+    void operator++();
+    Tile* operator*() {
+      return tiling_->EvictionTileForPriority(current_index_);
+    }
+
+   private:
+    PictureLayerTiling* tiling_;
+    size_t current_index_;
+  };
+
   ~PictureLayerTiling();
 
   // Create a tiling with no tiles.  CreateTiles must be called to add some.
@@ -159,6 +201,8 @@ class CC_EXPORT PictureLayerTiling {
     return frame_time_in_seconds != last_impl_frame_time_in_seconds_;
   }
 
+  size_t RequiredGPUMemoryInBytes() const;
+
   scoped_ptr<base::Value> AsValue() const;
   size_t GPUMemoryUsageInBytes() const;
 
@@ -183,6 +227,9 @@ class CC_EXPORT PictureLayerTiling {
   }
 
  protected:
+  friend class TilingRasterTileIterator;
+  friend class TilingEvictionTileIterator;
+
   typedef std::pair<int, int> TileMapKey;
   typedef base::hash_map<TileMapKey, scoped_refptr<Tile> > TileMap;
 
@@ -200,6 +247,10 @@ class CC_EXPORT PictureLayerTiling {
                             const gfx::Rect& visible_rect_in_content_space)
       const;
 
+  Tile* RasterTileForPriority(size_t priority_index);
+  Tile* EvictionTileForPriority(size_t priority_index);
+  bool HasVisibleTilesAtOrAfterPriority(size_t prioroity_index) const;
+
   // Given properties.
   float contents_scale_;
   gfx::Size layer_bounds_;
@@ -213,7 +264,18 @@ class CC_EXPORT PictureLayerTiling {
 
   // State saved for computing velocities based upon finite differences.
   double last_impl_frame_time_in_seconds_;
-  gfx::RectF last_visible_rect_in_content_space_;
+  gfx::Rect last_visible_rect_in_content_space_;
+
+  // Tile bins used to return tiles in raster and eviction iterators.
+  std::vector<Tile*> visible_tiles_;
+  std::vector<Tile*> skewport_tiles_;
+  bool skewport_tiles_sorted_;
+  std::vector<Tile*> eventually_tiles_;
+  bool eventually_tiles_sorted_;
+  std::vector<Tile*> eviction_tiles_;
+  bool eviction_tiles_sorted_;
+
+  WhichTree last_update_tree_;
 
   friend class CoverageIterator;