tracing: Make ConvertableToTraceFormat move-only scoped_ptr

base/trace_event/trace_config.cc

Index: base/trace_event/trace_config.cc
diff --git a/base/trace_event/trace_config.cc b/base/trace_event/trace_config.cc
index 8e11078ebc76842b12033642da5a9f4939f79092..d60c08124d29be4e5e65395eabec108da00cade8 100644
--- a/base/trace_event/trace_config.cc
+++ b/base/trace_event/trace_config.cc
@@ -63,13 +63,11 @@ class ConvertableTraceConfigToTraceFormat
  public:
   explicit ConvertableTraceConfigToTraceFormat(const TraceConfig& trace_config)
       : trace_config_(trace_config) {}
+  ~ConvertableTraceConfigToTraceFormat() override {}
   void AppendAsTraceFormat(std::string* out) const override {
     out->append(trace_config_.ToString());
   }
 
- protected:
-  ~ConvertableTraceConfigToTraceFormat() override {}
-
  private:
   const TraceConfig trace_config_;
 };
@@ -158,9 +156,9 @@ std::string TraceConfig::ToString() const {
   return json;
 }
 
-scoped_refptr<ConvertableToTraceFormat>
-TraceConfig::AsConvertableToTraceFormat() const {
-  return new ConvertableTraceConfigToTraceFormat(*this);
+scoped_ptr<ConvertableToTraceFormat> TraceConfig::AsConvertableToTraceFormat()
+    const {
+  return make_scoped_ptr(new ConvertableTraceConfigToTraceFormat(*this));
 }
 
 std::string TraceConfig::ToCategoryFilterString() const {