cc: Add a tiling iterator that doesn't include borders

cc/base/tiling_data.h

Index: cc/base/tiling_data.h
diff --git a/cc/base/tiling_data.h b/cc/base/tiling_data.h
index ee3a51ee77143e89709068e4b244dd1827a54564..d885c9bda6a5cd1065cf4a8c08eb4f9045bd6883 100644
--- a/cc/base/tiling_data.h
+++ b/cc/base/tiling_data.h
@@ -86,11 +86,13 @@ class CC_EXPORT TilingData {
     int index_y_;
   };
 
-  // Iterate through all indices whose bounds + border intersect with |rect|.
+  // Iterate through tiles whose bounds + optional border intersect with |rect|.
   class CC_EXPORT Iterator : public BaseIterator {
    public:
     Iterator();
-    Iterator(const TilingData* tiling_data, const gfx::Rect& tiling_rect);
+    Iterator(const TilingData* tiling_data,
+             const gfx::Rect& tiling_rect,
+             bool include_borders);
     Iterator& operator++();
 
    private: