tracing: Make ConvertableToTraceFormat move-only scoped_ptr

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 8b1227270b5f39e3cfefa936052e0f585d6c55e0..165b067cce37f855b33448b8afda14289a3ff413 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -3543,12 +3543,12 @@ base::TimeDelta LayerTreeHostImpl::CurrentBeginFrameInterval() const {
   return current_begin_frame_tracker_.Interval();
 }
 
-scoped_refptr<base::trace_event::ConvertableToTraceFormat>
+scoped_ptr<base::trace_event::ConvertableToTraceFormat>
 LayerTreeHostImpl::AsValueWithFrame(FrameData* frame) const {
-  scoped_refptr<base::trace_event::TracedValue> state =
-      new base::trace_event::TracedValue();
+  scoped_ptr<base::trace_event::TracedValue> state(
+      new base::trace_event::TracedValue());
   AsValueWithFrameInto(frame, state.get());
-  return state;
+  return std::move(state);
 }
 
 void LayerTreeHostImpl::AsValueWithFrameInto(