Remove implicit conversions from scoped_refptr to T* in cc/trees/

cc/trees/layer_tree_host_perftest.cc

Index: cc/trees/layer_tree_host_perftest.cc
diff --git a/cc/trees/layer_tree_host_perftest.cc b/cc/trees/layer_tree_host_perftest.cc
index 49ef6e1cd1df591e79632b4d5ad541405f763e57..999ab3f02c0591c044536cd2719897945f1ad687 100644
--- a/cc/trees/layer_tree_host_perftest.cc
+++ b/cc/trees/layer_tree_host_perftest.cc
@@ -184,7 +184,8 @@ class LayerTreeHostPerfTestLeafInvalidates
     // Find a leaf layer.
     for (layer_to_invalidate_ = layer_tree_host()->root_layer();
          layer_to_invalidate_->children().size();
-         layer_to_invalidate_ = layer_to_invalidate_->children()[0]) {}
+         layer_to_invalidate_ = layer_to_invalidate_->children()[0].get()) {
+    }
   }
 
   virtual void DidCommitAndDrawFrame() OVERRIDE {