tracing: Make ConvertableToTraceFormat move-only scoped_ptr

ui/compositor/layer_unittest.cc

Index: ui/compositor/layer_unittest.cc
diff --git a/ui/compositor/layer_unittest.cc b/ui/compositor/layer_unittest.cc
index 27121fc35f9740f2fa4c237556c09e4a27ecbc90..eaf68aeb1af59064cde00a2880343f4747261d6e 100644
--- a/ui/compositor/layer_unittest.cc
+++ b/ui/compositor/layer_unittest.cc
@@ -695,8 +695,8 @@ TEST_F(LayerWithNullDelegateTest, EscapedDebugNames) {
   scoped_ptr<Layer> layer(CreateLayer(LAYER_NOT_DRAWN));
   std::string name = "\"\'\\/\b\f\n\r\t\n";
   layer->set_name(name);
-  scoped_refptr<base::trace_event::ConvertableToTraceFormat> debug_info =
-    layer->TakeDebugInfo(layer->cc_layer_for_testing());
+  scoped_ptr<base::trace_event::ConvertableToTraceFormat> debug_info(
+      layer->TakeDebugInfo(layer->cc_layer_for_testing()));
   EXPECT_TRUE(debug_info.get());
   std::string json;
   debug_info->AppendAsTraceFormat(&json);