ice-restart: fix functionality

by listening to the transport selectedcandidatepairchange event.
This sample has been relying on the somewhat buggy but useful behavior
of the "legacy" iceconnectionstatechange firing a "connected" event even
if the previous state was already connected.

This behavior is no longer supported in the spec iceconnectionstatechange
event. Alternatively listen to the selectedcandidatepairchange event and
determine the availability of new candidates based on that

package.json

@@ -30,7 +30,7 @@
   ],
   "devDependencies": {
     "chai": "^4.3.6",
-    "chromedriver": "^98.0.1",
+    "chromedriver": ">98.0.1",
     "eslint": "^8.9.0",
     "eslint-config-google": "^0.14.0",
     "geckodriver": "^3.0.1",

src/content/peerconnection/restart-ice/js/main.js

@@ -32,6 +32,8 @@ remoteVideo.addEventListener('loadedmetadata', function() {
   console.log(`Remote video videoWidth: ${this.videoWidth}px,  videoHeight: ${this.videoHeight}px`);
 });
 
+const useSelectedCandidatePairChange = window.RTCIceTransport && 'onselectedcandidatepairchange' in RTCIceTransport.prototype;
+
 remoteVideo.onresize = () => {
   console.log(`Remote video size changed to ${remoteVideo.videoWidth}x${remoteVideo.videoHeight}`);
   // We'll use the first onsize callback as an indication that video has started
@@ -170,6 +172,18 @@ function onCreateAnswerSuccess(desc) {
   pc2.setLocalDescription(desc).then(() => onSetLocalSuccess(pc2), onSetSessionDescriptionError);
   console.log('pc1 setRemoteDescription start');
   pc1.setRemoteDescription(desc).then(() => onSetRemoteSuccess(pc1), onSetSessionDescriptionError);
+
+  if (useSelectedCandidatePairChange) {
+    pc1.getSenders()[0].transport.iceTransport.onselectedcandidatepairchange = () => {
+      checkStats(pc1);
+      if (pc1.iceConnectionState === 'connected') {
+        restartButton.disabled = false;
+      }
+    };
+    pc2.getSenders()[0].transport.iceTransport.onselectedcandidatepairchange = () => {
+      checkStats(pc2);
+    };
+  }
 }
 
 function onIceCandidate(pc, event) {
@@ -191,10 +205,11 @@ function onIceStateChange(pc, event) {
   if (pc) {
     console.log(`${getName(pc)} ICE state: ${pc.iceConnectionState}`);
     console.log('ICE state change event: ', event);
-    // TODO: get rid of this in favor of http://w3c.github.io/webrtc-pc/#widl-RTCIceTransport-onselectedcandidatepairchange
-    if (pc.iceConnectionState === 'connected' ||
-      pc.iceConnectionState === 'completed') {
-      checkStats(pc);
+    if (!useSelectedCandidatePairChange) {
+      if (pc.iceConnectionState === 'connected' ||
+        pc.iceConnectionState === 'completed') {
+        checkStats(pc);
+      }
     }
   }
 }

src/content/peerconnection/restart-ice/js/test.js

@@ -16,7 +16,7 @@ let driver;
 const path = '/src/content/peerconnection/restart-ice/index.html';
 const url = `${process.env.BASEURL ? process.env.BASEURL : ('file://' + process.cwd())}${path}`;
 
-describe.skip('peerconnection ice restart', () => {
+describe('peerconnection ice restart', () => {
   before(() => {
     driver = seleniumHelpers.buildDriver();
   });
@@ -58,7 +58,6 @@ describe.skip('peerconnection ice restart', () => {
     await driver.wait(() => driver.findElement(webdriver.By.id('restartButton')).isEnabled());
     await driver.findElement(webdriver.By.id('restartButton')).click();
 
-    await driver.wait(() => !driver.findElement(webdriver.By.id('restartButton')).isEnabled());
     await driver.wait(() => driver.findElement(webdriver.By.id('restartButton')).isEnabled());
 
     const secondCandidateIds = await Promise.all([