cc: Remove vectors from tiling eviction tile iterator.

cc/layers/picture_layer_impl.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_LAYERS_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 59 matching lines @@
     LayerEvictionTileIterator(PictureLayerImpl* layer,
                               TreePriority tree_priority);
     ~LayerEvictionTileIterator();
 
     Tile* operator*();
     const Tile* operator*() const;
     LayerEvictionTileIterator& operator++();
     operator bool() const;
 
    private:
+    enum RangeType {
+      HIGHER_THAN_HIGH_RES,
+      LOWER_THAN_LOW_RES,
+      BETWEEN_HIGH_AND_LOW_RES,
+      LOW_RES,
+      HIGH_RES,
+      NUM_RANGE_TYPES
+    };
+    struct TilingIterationRange {
+      int start_index;
+      int one_past_end_index;
+    };
+    struct IterationStage {
+      IterationStage(TilePriority::PriorityBin type, bool is_required)
+          : tile_type(type), required_for_activation(is_required) {}
+
+      TilePriority::PriorityBin tile_type;
+      bool required_for_activation;
+    };
+
+    void ConstructRanges();
+    bool CurrentTilingIndexInRange();
     void AdvanceToNextIterator();
-    bool IsCorrectType(
-        PictureLayerTiling::TilingEvictionTileIterator* it) const;
+    bool AdvanceTiling();
+    bool AdvanceRange();
+    bool AdvanceStage();
 
-    std::vector<PictureLayerTiling::TilingEvictionTileIterator> iterators_;
-    size_t iterator_index_;
-    TilePriority::PriorityBin iteration_stage_;
-    bool required_for_activation_;
+    PictureLayerTiling::TilingEvictionTileIterator iterator_;
+    int current_tiling_index_;
+    RangeType current_range_type_;
+    IterationStage current_stage_;
 
+    TilingIterationRange ranges_[NUM_RANGE_TYPES];
+    TreePriority tree_priority_;
     PictureLayerImpl* layer_;
   };
 
   static scoped_ptr<PictureLayerImpl> Create(LayerTreeImpl* tree_impl, int id) {
     return make_scoped_ptr(new PictureLayerImpl(tree_impl, id));
   }
   virtual ~PictureLayerImpl();
 
   // LayerImpl overrides.
   virtual const char* LayerTypeAsString() const OVERRIDE;
@@ skipping 118 matching lines @@
   gfx::Size viewport_size_for_tile_priority_;
   gfx::Transform screen_space_transform_for_tile_priority_;
 
   friend class PictureLayer;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_