[eslint] no-undef-init

.eslintrc.js

         'no-restricted-globals': 0,
         'no-shadow-restricted-names': 2,
         'no-undef': 2,
+        'no-undef-init': 2,
         'no-undefined': 0,
         'no-unused-vars': 2,
 

modules/RTC/RTC.js

      * @private
      */
     _getRemoteTrackById(streamId, trackId) {
-        let result = undefined;
+        let result;
 
         // .find will break the loop once the first match is found
         Object.keys(this.remoteTracks).find(endpoint => {

modules/RTC/RTCUtils.js

 
 let currentlyAvailableMediaDevices;
 
-let rawEnumerateDevicesWithCallback = undefined;
+let rawEnumerateDevicesWithCallback;
 /**
  * "rawEnumerateDevicesWithCallback" will be initialized only after WebRTC is
  * ready. Otherwise it is too early to assume that the devices listing is not