fix(proxy): provide way to clean up some RTC state

modules/RTC/RTC.js

@@ -189,16 +189,51 @@ export default class RTC extends Listenable {
         // The last N change listener.
         this._lastNChangeListener = this._onLastNChanged.bind(this);
 
+        this._onDeviceListChanged = this._onDeviceListChanged.bind(this);
+        this._updateAudioOutputForAudioTracks
+            = this._updateAudioOutputForAudioTracks.bind(this);
+
         // Switch audio output device on all remote audio tracks. Local audio
         // tracks handle this event by themselves.
         if (RTCUtils.isDeviceChangeAvailable('output')) {
-            RTCUtils.addListener(RTCEvents.AUDIO_OUTPUT_DEVICE_CHANGED,
-                deviceId => this._updateAudioOutputForAudioTracks(deviceId));
+            RTCUtils.addListener(
+                RTCEvents.AUDIO_OUTPUT_DEVICE_CHANGED,
+                this._updateAudioOutputForAudioTracks
+            );
 
             RTCUtils.addListener(
                 RTCEvents.DEVICE_LIST_CHANGED,
-                () => this._updateAudioOutputForAudioTracks(
-                    RTCUtils.getAudioOutputDevice()));
+                this._onDeviceListChanged
+            );
+        }
+    }
+
+    /**
+     * Removes any listeners and stored state from this {@code RTC} instance.
+     *
+     * @returns {void}
+     */
+    destroy() {
+        RTCUtils.removeListener(
+            RTCEvents.AUDIO_OUTPUT_DEVICE_CHANGED,
+            this._updateAudioOutputForAudioTracks
+        );
+
+        RTCUtils.removeListener(
+            RTCEvents.DEVICE_LIST_CHANGED,
+            this._onDeviceListChanged
+        );
+
+        this.removeListener(
+            RTCEvents.LASTN_ENDPOINT_CHANGED,
+            this._lastNChangeListener
+        );
+
+        if (this._channelOpenListener) {
+            this.removeListener(
+                RTCEvents.DATA_CHANNEL_OPEN,
+                this._channelOpenListener
+            );
         }
     }
 
@@ -302,6 +337,18 @@ export default class RTC extends Listenable {
             this._lastNChangeListener);
     }
 
+    /**
+     * Callback invoked when the list of known audio and video devices has
+     * been updated. Attempts to update the known available audio output
+     * devices.
+     *
+     * @private
+     * @returns {void}
+     */
+    _onDeviceListChanged() {
+        this._updateAudioOutputForAudioTracks(RTCUtils.getAudioOutputDevice());
+    }
+
     /**
      * Receives events when Last N had changed.
      * @param {array} lastNEndpoints The new Last N endpoints.

modules/proxyconnection/ProxyConnectionPC.js

@@ -231,14 +231,14 @@ export default class ProxyConnectionPC {
          * of {@code RTC} from elsewhere should not be re-used because it is
          * a stateful grouping of utilities.
          */
-        const rtc = new RTC(this, {});
+        this._rtc = new RTC(this, {});
 
         /**
          * Add the remote track listener here as {@code JingleSessionPC} has
          * {@code TraceablePeerConnection} which uses {@code RTC}'s event
          * emitter.
          */
-        rtc.addListener(
+        this._rtc.addListener(
             RTCEvents.REMOTE_TRACK_ADDED,
             this._onRemoteStream
         );
@@ -261,7 +261,7 @@ export default class ProxyConnectionPC {
          * An additional initialize call is necessary to properly set instance
          * variable for calling.
          */
-        peerConnection.initialize(roomStub, rtc, configStub);
+        peerConnection.initialize(roomStub, this._rtc, configStub);
 
         return peerConnection;
     }
@@ -364,11 +364,18 @@ export default class ProxyConnectionPC {
         this._tracks.forEach(track => track.dispose());
         this._tracks = [];
 
-        if (!this._peerConnection) {
-            return;
+        if (this._peerConnection) {
+            this._peerConnection.onTerminated();
         }
 
-        this._peerConnection.onTerminated();
+        if (this._rtc) {
+            this._rtc.removeListener(
+                RTCEvents.REMOTE_TRACK_ADDED,
+                this._onRemoteStream
+            );
+
+            this._rtc.destroy();
+        }
     }
 
     /**