Convert JsonWriter::Write to taking a const ref for the in-param

dbus/values_util.cc

Index: dbus/values_util.cc
diff --git a/dbus/values_util.cc b/dbus/values_util.cc
index c27c2723b84cb9f42820d22ffe6cb8fc96ff1cd6..c162878ee05eb1392f807eb177af783600af5f32 100644
--- a/dbus/values_util.cc
+++ b/dbus/values_util.cc
@@ -48,10 +48,10 @@ bool PopDictionaryEntries(MessageReader* reader,
     } else {
       // If the type of keys is not STRING, convert it to string.
       scoped_ptr<base::Value> key(PopDataAsValue(&entry_reader));
-      if (!key.get())
+      if (!key)
         return false;
       // Use JSONWriter to convert an arbitrary value to a string.
-      base::JSONWriter::Write(key.get(), &key_string);
+      base::JSONWriter::Write(*key, &key_string);
     }
     // Get the value and set the key-value pair.
     base::Value* value = PopDataAsValue(&entry_reader);