tracing: Make ConvertableToTraceFormat move-only scoped_ptr

cc/output/begin_frame_args.cc

Index: cc/output/begin_frame_args.cc
diff --git a/cc/output/begin_frame_args.cc b/cc/output/begin_frame_args.cc
index c50d5f8346a43905d685f6acc146afd4bc3f2807..98f0a3e446f616744735c27b7fa4ce65adec4513 100644
--- a/cc/output/begin_frame_args.cc
+++ b/cc/output/begin_frame_args.cc
@@ -98,12 +98,12 @@ BeginFrameArgs BeginFrameArgs::Create(BeginFrameArgs::CreationLocation location,
 #endif
 }
 
-scoped_refptr<base::trace_event::ConvertableToTraceFormat>
+scoped_ptr<base::trace_event::ConvertableToTraceFormat>
 BeginFrameArgs::AsValue() 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());
   AsValueInto(state.get());
-  return state;
+  return std::move(state);
 }
 
 void BeginFrameArgs::AsValueInto(base::trace_event::TracedValue* state) const {