Stop doing unnecessary UTF-8 to UTF-16 conversions in JSONWriter.

jingle/notifier/listener/notification_defines.cc

Index: jingle/notifier/listener/notification_defines.cc
diff --git a/jingle/notifier/listener/notification_defines.cc b/jingle/notifier/listener/notification_defines.cc
index f4f3e408a5b795f8fa80826cdae43158d9479706..f7c8f8fd3ad5dd8fe90af742720f7a6c137efb87 100644
--- a/jingle/notifier/listener/notification_defines.cc
+++ b/jingle/notifier/listener/notification_defines.cc
@@ -65,10 +65,12 @@ bool Notification::Equals(const Notification& other) const {
 }
 
 std::string Notification::ToString() const {
-  // |channel| or |data| could hold binary data, so use GetDoubleQuotedJson()
-  // to escape them.
-  const std::string& printable_channel = base::GetDoubleQuotedJson(channel);
-  const std::string& printable_data = base::GetDoubleQuotedJson(data);
+  // |channel| or |data| could hold binary data, so convert all non-ASCII
+  // characters to escape sequences.
+  const std::string& printable_channel =
+      base::EscapeBytesAsInvalidJSONString(channel, true /* put_in_quotes */);
+  const std::string& printable_data =
+      base::EscapeBytesAsInvalidJSONString(data, true /* put_in_quotes */);
   return
       "{ channel: " + printable_channel + ", data: " + printable_data + " }";
 }