Update the nine patch layer to use UI resources

cc/layers/scrollbar_layer_unittest.cc

Index: cc/layers/scrollbar_layer_unittest.cc
diff --git a/cc/layers/scrollbar_layer_unittest.cc b/cc/layers/scrollbar_layer_unittest.cc
index e62a032d6a3ce53acf5757dfa976ad7dc4200f43..2e1b4b6f483e320413d69e15829392bb8e94cdbb 100644
--- a/cc/layers/scrollbar_layer_unittest.cc
+++ b/cc/layers/scrollbar_layer_unittest.cc
@@ -525,7 +525,8 @@ class MockLayerTreeHost : public LayerTreeHost {
   virtual UIResourceId CreateUIResource(UIResourceClient* content) OVERRIDE {
     total_ui_resource_created_++;
     UIResourceId nid = next_id_++;
-    ui_resource_bitmap_map_[nid] = content->GetBitmap(nid, false);
+    ui_resource_bitmap_map_.insert(
+        std::make_pair(nid, content->GetBitmap(nid, false)));
     return nid;
   }
 
@@ -544,13 +545,13 @@ class MockLayerTreeHost : public LayerTreeHost {
 
   gfx::Size ui_resource_size(UIResourceId id) {
     UIResourceBitmapMap::iterator iter = ui_resource_bitmap_map_.find(id);
-    if (iter != ui_resource_bitmap_map_.end() && iter->second.get())
-      return iter->second->GetSize();
+    if (iter != ui_resource_bitmap_map_.end())
+      return iter->second.GetSize();
     return gfx::Size();
   }
 
  private:
-  typedef base::hash_map<UIResourceId, scoped_refptr<UIResourceBitmap> >
+  typedef base::hash_map<UIResourceId, UIResourceBitmap>
       UIResourceBitmapMap;
   UIResourceBitmapMap ui_resource_bitmap_map_;