Removes hard-coded constants and uses the events API in the statistics

module.

modules/connectionquality/connectionquality.js

 var eventEmitter = new EventEmitter();
 var CQEvents = require("../../service/connectionquality/CQEvents");
 var XMPPEvents = require("../../service/xmpp/XMPPEvents");
+var StatisticsEvents = require("../../service/statistics/Events");
 
 /**
  * local stats
 var ConnectionQuality = {
     init: function () {
         APP.xmpp.addListener(XMPPEvents.REMOTE_STATS, this.updateRemoteStats);
-        APP.statistics.addConnectionStatsListener(this.updateLocalStats);
-        APP.statistics.addRemoteStatsStopListener(this.stopSendingStats);
-
+        APP.statistics.addListener(StatisticsEvents.CONNECTION_STATS,
+                                   this.updateLocalStats);
+        APP.statistics.addListener(StatisticsEvents.STOP,
+                                   this.stopSendingStats);
     },
 
     /**

modules/statistics/LocalStatsCollector.js

  */
 
 var RTCBrowserType = require('../RTC/RTCBrowserType');
+var StatisticsEvents = require('../../service/statistics/Events');
 
 var LOCAL_JID = require("../../service/statistics/constants").LOCAL_JID;
 
             if (audioLevel != self.audioLevel) {
                 self.audioLevel = animateLevel(audioLevel, self.audioLevel);
                 self.eventEmitter.emit(
-                    "statistics.audioLevel",
-                    LOCAL_JID,
+                    StatisticsEvents.AUDIO_LEVEL,
+                    self.statisticsService.LOCAL_JID,
                     self.audioLevel);
             }
         },

modules/statistics/RTPStatsCollector.js

 
 var logger = require("jitsi-meet-logger").getLogger(__filename);
 var RTCBrowserType = require("../RTC/RTCBrowserType");
+var StatisticsEvents = require("../../service/statistics/Events");
 
 /* Whether we support the browser we are running into for logging statistics */
 var browserSupported = RTCBrowserType.isChrome() ||
         upload:
             calculatePacketLoss(lostPackets.upload, totalPackets.upload)
     };
-    this.eventEmitter.emit("statistics.connectionstats",
+    this.eventEmitter.emit(StatisticsEvents.CONNECTION_STATS,
         {
             "bitrate": this.conferenceStats.bitrate,
             "packetLoss": this.conferenceStats.packetLoss,
             // but it seems to vary between 0 and around 32k.
             audioLevel = audioLevel / 32767;
             ssrcStats.setSsrcAudioLevel(ssrc, audioLevel);
-            this.eventEmitter.emit("statistics.audioLevel", ssrc, audioLevel);
+            this.eventEmitter.emit(
+                StatisticsEvents.AUDIO_LEVEL, ssrc, audioLevel);
         }
     }
 };

modules/statistics/statistics.js

 var LocalStats = require("./LocalStatsCollector.js");
 var RTPStats = require("./RTPStatsCollector.js");
 var EventEmitter = require("events");
+var StatisticsEvents = require("../../service/statistics/Events");
 //var StreamEventTypes = require("../../service/RTC/StreamEventTypes.js");
 //var XMPPEvents = require("../../service/xmpp/XMPPEvents");
 //var CallStats = require("./CallStats");
 
 Statistics.prototype.addAudioLevelListener = function(listener)
 {
-    this.eventEmitter.on("statistics.audioLevel", listener);
+    this.eventEmitter.on(StatisticsEvents.AUDIO_LEVEL, listener);
 }
 
 Statistics.prototype.removeAudioLevelListener = function(listener)
 {
-    this.eventEmitter.removeListener("statistics.audioLevel", listener);
+    this.eventEmitter.removeListener(StatisticsEvents.AUDIO_LEVEL, listener);
 }
 
 Statistics.prototype.dispose = function () {
 Statistics.prototype.stopRemote = function () {
     if (this.rtpStats) {
         this.rtpStats.stop();
-        this.eventEmitter.emit("statistics.stop");
+        this.eventEmitter.emit(StatisticsEvents.STOP);
         this.rtpStats = null;
     }
 }

service/statistics/Events.js

+module.exports = {
+    /**
+     * An event carrying connection statistics.
+     */
+    CONNECTION_STATS: "statistics.connectionstats",
+    /**
+     * FIXME: needs documentation.
+     */
+    AUDIO_LEVEL: "statistics.audioLevel",
+    /**
+     * FIXME: needs documentation.
+     */
+    STOP: "statistics.stop"
+};