Enables adapter and desktop sharing for Edge.

* Enables adapter for edge.

We were not filtering correctly all unsupported iceServers and an error is thrown and no connection is established.

* Enable desktop sharing for Edge.

Currently when replacing video track with desktop sharing one, doesn't work because of: https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/17528460/
If Edge user joins first and enables desktop sharing it will work when others join. Tried also to use replaceTrack/setTrack as a workaround, but again we hit an error, this time InvalidAccessError.

* Adds the helper function usesAdapter in BrowserCaps.

modules/RTC/RTCUtils.js

 // Require adapter only for certain browsers. This is being done for
 // react-native, which has its own shims, and while browsers are being migrated
 // over to use adapter's shims.
-if (browser.usesNewGumFlow()) {
+if (browser.usesAdapter()) {
     require('webrtc-adapter');
 }
 

modules/RTC/ScreenObtainer.js

             }
 
             return this.obtainScreenOnFirefox;
+        } else if (browser.isEdge() && navigator.getDisplayMedia) {
+            return (_, onSuccess, onFailure) => {
+                navigator.getDisplayMedia({ video: true })
+                    .then(stream => onSuccess({
+                        stream,
+                        sourceId: stream.id
+                    }))
+                    .catch(onFailure);
+            };
         }
 
         logger.log(

modules/RTC/ortc/RTCPeerConnection.js

         this._dtlsTransport = dtlsTransport;
     }
 
-    /**
-     * Pares STUN and TURN servers to only one. This works around an issue on
-     * edge where an error occurs if multiple are declared.
-     * See https://developer.microsoft.com/en-us/microsoft-edge/platform
-     * /issues/10163458
-     *
-     * @param {array} servers - All STUN AND TURN servers to connect to.
-     * @private
-     * @returns {array} An array with only one STUN server and one TURN server
-     * at the most.
-     */
-    _filterServers(servers = []) {
-        const filteredServers = [];
-        const firstStun = servers.find(server => server.url.startsWith('stun'));
-
-        if (firstStun) {
-            filteredServers.push(firstStun);
-        }
-
-        const firstTurn = servers.find(server => server.url.startsWith('turn'));
-
-        if (firstTurn) {
-            filteredServers.push(firstTurn);
-        }
-
-        return filteredServers;
-    }
-
     /**
      * Creates the RTCIceGatherer.
      * @private
     _setIceGatherer(pcConfig) {
         const iceGatherOptions = {
             gatherPolicy: pcConfig.iceTransportPolicy || 'all',
-            iceServers: this._filterServers(pcConfig.iceServers)
+            iceServers: pcConfig.iceServers
         };
         const iceGatherer = new RTCIceGatherer(iceGatherOptions);
 

modules/browser/BrowserCapabilities.js

             || this.isSafariWithWebrtc();
 
     }
+
+    /**
+     * Checks if the browser uses webrtc-adapter. All browsers using the new
+     * getUserMedia flow and Edge.
+     *
+     * @returns {boolean}
+     */
+    usesAdapter() {
+        return this.usesNewGumFlow() || this.isEdge();
+    }
 }