Moves require to top for the RTC module.

modules/RTC/MediaStream.js

-var RTC = require("./RTC.js");
 ////These lines should be uncommented when require works in app.js
 //var RTCBrowserType = require("../../service/RTC/RTCBrowserType.js");
 //var StreamEventTypes = require("../../service/RTC/StreamEventTypes.js");
  *
  * @constructor
  */
-function MediaStream(data, sid, ssrc, eventEmmiter) {
+function MediaStream(data, sid, ssrc, eventEmmiter, browser) {
     this.sid = sid;
     this.stream = data.stream;
     this.peerjid = data.peerjid;
         MediaStreamType.VIDEO_TYPE : MediaStreamType.AUDIO_TYPE;
     this.muted = false;
     eventEmmiter.emit(StreamEventTypes.EVENT_TYPE_REMOTE_CREATED, this);
+    if(browser == RTCBrowserType.RTC_BROWSER_FIREFOX)
+    {
+        if (!this.getVideoTracks)
+            this.getVideoTracks = function () { return []; };
+        if (!this.getAudioTracks)
+            this.getAudioTracks = function () { return []; };
+    }
 }
 
-if(RTC.getBrowserType() == RTCBrowserType.RTC_BROWSER_FIREFOX)
-{
-    if (!MediaStream.prototype.getVideoTracks)
-        MediaStream.prototype.getVideoTracks = function () { return []; };
-    if (!MediaStream.prototype.getAudioTracks)
-        MediaStream.prototype.getAudioTracks = function () { return []; };
-}
 
 MediaStream.prototype.getOriginalStream = function()
 {

modules/RTC/RTC.js

 var EventEmitter = require("events");
 var RTCUtils = require("./RTCUtils.js");
+var LocalStream = require("./LocalStream.js");
+var DataChannels = require("./DataChannels");
+var MediaStream = require("./MediaStream.js");
 //These lines should be uncommented when require works in app.js
 //var StreamEventTypes = require("../../service/RTC/StreamEventTypes.js");
 //var XMPPEvents = require("../service/xmpp/XMPPEvents");
         eventEmitter.removeListener(eventType, listener);
     },
     createLocalStream: function (stream, type) {
-        var LocalStream = require("./LocalStream.js");
+
         var localStream =  new LocalStream(stream, type, eventEmitter);
         this.localStreams.push(localStream);
         if(type == "audio")
         }
     },
     createRemoteStream: function (data, sid, thessrc) {
-        var MediaStream = require("./MediaStream.js")
-        var remoteStream = new MediaStream(data, sid, thessrc, eventEmitter);
+        var remoteStream = new MediaStream(data, sid, thessrc, eventEmitter,
+            this.getBrowserType());
         var jid = data.peerjid || connection.emuc.myroomjid;
         if(!this.remoteStreams[jid]) {
             this.remoteStreams[jid] = {};
         this.rtcUtils.obtainAudioAndVideoPermissions();
     },
     onConferenceCreated: function(event) {
-        var DataChannels = require("./DataChannels");
         DataChannels.bindDataChannelListener(event.peerconnection);
     },
     muteRemoteVideoStream: function (jid, value) {