Raster display item lists via a visual rect RTree.

cc/base/rtree.h

Index: cc/base/rtree.h
diff --git a/cc/base/rtree.h b/cc/base/rtree.h
index 63f7d14f52c20d96ea0378b43749bd98831f344e..b9bc0fbeb2b3933b7297ff1ebd0bf09557ae9417 100644
--- a/cc/base/rtree.h
+++ b/cc/base/rtree.h
@@ -9,7 +9,7 @@
 #include <vector>
 
 #include "cc/base/cc_export.h"
-#include "ui/gfx/geometry/rect_f.h"
+#include "ui/gfx/geometry/rect.h"
 
 namespace cc {
 
@@ -75,6 +75,8 @@ class CC_EXPORT RTree {
 
   void Search(const gfx::Rect& query, std::vector<size_t>* results) const;
 
+  gfx::Rect GetBounds() const;
+
  private:
   // These values were empirically determined to produce reasonable performance
   // in most cases.