fix(RTCBrowserType): remove duplication

There was 'supportsSimulcast' method already, so removing
'isSimulcastSupported'.

modules/RTC/RTCBrowserType.js

@@ -107,17 +107,6 @@ const RTCBrowserType = {
         return currentBrowser === RTCBrowserType.RTC_BROWSER_SAFARI;
     },
 
-    /**
-     * Checks if the current client supports Simulcast.
-     * @return {boolean} <tt>true</tt> if Simulcast is supported or
-     * <tt>false</tt> otherwise.
-     */
-    isSimulcastSupported() {
-        // Possibly it could work with anything that uses "official" WebRTC
-        // stack, but only Chrome was tested.
-        return RTCBrowserType.isChrome();
-    },
-
     /**
      * Checks if current environment is NWJS.
      * @returns {boolean}
@@ -223,10 +212,9 @@ const RTCBrowserType = {
      * @returns {boolean}
      */
     supportsSimulcast() {
-        // This mirrors what sdp-simulcast uses (which is used when deciding
-        // whether to actually enable simulcast or not).
-        // TODO: the logic should be in one single place.
-        return window.chrome !== undefined;
+        return RTCBrowserType.isChrome()
+            || RTCBrowserType.isElectron()
+            || RTCBrowserType.isNWJS();
     },
 
     supportsRtx() {

modules/RTC/TraceablePeerConnection.js

@@ -356,7 +356,7 @@ TraceablePeerConnection.prototype._getDesiredMediaDirection
  */
 TraceablePeerConnection.prototype.isSimulcastOn = function() {
     return !this.options.disableSimulcast
-        && RTCBrowserType.isSimulcastSupported()
+        && RTCBrowserType.supportsSimulcast()
         && !this.isP2P;
 };