Bug 1000499 - JavaScript Error: "this.removeMessageListener is not a function". r=dimi

dom/system/gonk/NfcContentHelper.js

@@ -362,7 +362,7 @@ NfcContentHelper.prototype = {
   // nsIObserver
   observe: function observe(subject, topic, data) {
     if (topic == "xpcom-shutdown") {
-      this.removeMessageListener();
+      this.destroyDOMRequestHelper();
       Services.obs.removeObserver(this, "xpcom-shutdown");
       cpmm = null;
     }