tracing: Make ConvertableToTraceFormat move-only scoped_ptr

cc/test/ordered_simple_task_runner.cc

Index: cc/test/ordered_simple_task_runner.cc
diff --git a/cc/test/ordered_simple_task_runner.cc b/cc/test/ordered_simple_task_runner.cc
index dea8556d52790a90b4f4f7b10548097898e6ed9b..2452377b292d62f6bfe2bed0b6da518be76eb0b3 100644
--- a/cc/test/ordered_simple_task_runner.cc
+++ b/cc/test/ordered_simple_task_runner.cc
@@ -64,12 +64,11 @@ bool TestOrderablePendingTask::operator<(
   return ShouldRunBefore(other);
 }
 
-scoped_refptr<base::trace_event::ConvertableToTraceFormat>
+scoped_ptr<base::trace_event::ConvertableToTraceFormat>
 TestOrderablePendingTask::AsValue() const {
-  scoped_refptr<base::trace_event::TracedValue> state =
-      new base::trace_event::TracedValue();
+  auto state = make_scoped_ptr(new base::trace_event::TracedValue);
   AsValueInto(state.get());
-  return state;
+  return std::move(state);
 }
 
 void TestOrderablePendingTask::AsValueInto(
@@ -261,12 +260,11 @@ bool OrderedSimpleTaskRunner::RunForPeriod(base::TimeDelta period) {
 }
 
 // base::trace_event tracing functionality
-scoped_refptr<base::trace_event::ConvertableToTraceFormat>
+scoped_ptr<base::trace_event::ConvertableToTraceFormat>
 OrderedSimpleTaskRunner::AsValue() const {
-  scoped_refptr<base::trace_event::TracedValue> state =
-      new base::trace_event::TracedValue();
+  auto state = make_scoped_ptr(new base::trace_event::TracedValue);
   AsValueInto(state.get());
-  return state;
+  return std::move(state);
 }
 
 void OrderedSimpleTaskRunner::AsValueInto(