cc: Optimize picture layer tiling raster tile iterator.

cc/resources/picture_layer_tiling.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_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 55 matching lines @@
           return TilePriority::SOON;
         case EVENTUALLY_RECT:
           return TilePriority::EVENTUALLY;
       }
       NOTREACHED();
       return TilePriority::EVENTUALLY;
     }
 
     TilingRasterTileIterator& operator++();
 
-    gfx::Rect TileBounds() const {
-      DCHECK(*this);
-      if (phase_ == VISIBLE_RECT) {
-        return tiling_->tiling_data_.TileBounds(visible_iterator_.index_x(),
-                                                visible_iterator_.index_y());
-      }
-      return tiling_->tiling_data_.TileBounds(spiral_iterator_.index_x(),
-                                              spiral_iterator_.index_y());
-    }
-
    private:
     enum Phase {
       VISIBLE_RECT,
       SKEWPORT_RECT,
       SOON_BORDER_RECT,
       EVENTUALLY_RECT
     };
 
     void AdvancePhase();
     bool TileNeedsRaster(Tile* tile) const {
       RasterMode mode = tile->DetermineRasterModeForTree(tree_);
       return tile->NeedsRasterForMode(mode);
     }
 
     PictureLayerTiling* tiling_;
 
     Phase phase_;
-    gfx::Rect visible_rect_in_content_space_;
-    gfx::Rect skewport_in_content_space_;
-    gfx::Rect eventually_rect_in_content_space_;
-    gfx::Rect soon_border_rect_in_content_space_;
     WhichTree tree_;
 
     Tile* current_tile_;
     TilingData::Iterator visible_iterator_;
     TilingData::SpiralDifferenceIterator spiral_iterator_;
   };
 
   class CC_EXPORT TilingEvictionTileIterator {
    public:
     TilingEvictionTileIterator();
@@ skipping 200 matching lines @@
   // State saved for computing velocities based upon finite differences.
   double last_impl_frame_time_in_seconds_;
   gfx::Rect last_visible_rect_in_content_space_;
 
   // Iteration rects in content space
   gfx::Rect current_visible_rect_;
   gfx::Rect current_skewport_rect_;
   gfx::Rect current_soon_border_rect_;
   gfx::Rect current_eventually_rect_;
 
+  bool has_visible_rect_tiles_;
+  bool has_skewport_rect_tiles_;
+  bool has_soon_border_rect_tiles_;
+  bool has_eventually_rect_tiles_;
+
   std::vector<Tile*> eviction_tiles_cache_;
   bool eviction_tiles_cache_valid_;
   TreePriority eviction_cache_tree_priority_;
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_