test: Fix test failure waiting for passed time (#6580)

In some rare cases, particularly on Fuchsia-based Chromecasts at the moment, I am seeing test failures where the test is waiting for a time that has already passed. It appears that the `timeupdate` events may be missed in some cases. The `currentTime` appears to be less than the target at the last `timeupdate` event, then the time progresses internally, then a buffering state is hit and no new `timeupdate` events fire. So the Waiter class should use a timer for this as it does for many other types of waits.

test/test/util/waiter.js

@@ -115,25 +115,31 @@ shaka.test.Waiter = class {
     const goalName = 'movement from ' + mediaElement.currentTime +
                      ' to ' + timeGoal;
 
+    // The cleanup on timeout
+    let timer = null;
+    const cleanup = () => {
+      if (timer) {
+        timer.stop();
+      }
+      this.eventManager_.unlisten(mediaElement, 'timeupdate');
+      this.eventManager_.unlisten(mediaElement, 'ended');
+    };
+
     // The conditions for success
     const p = new Promise((resolve) => {
       const check = () => {
         if (mediaElement.currentTime >= timeGoal || mediaElement.ended) {
-          this.eventManager_.unlisten(mediaElement, 'timeupdate');
-          this.eventManager_.unlisten(mediaElement, 'ended');
+          cleanup();
           resolve();
         }
       };
+
+      timer = new shaka.util.Timer(check);
+      timer.tickEvery(/* seconds= */ 1);
       this.eventManager_.listen(mediaElement, 'timeupdate', check);
       this.eventManager_.listen(mediaElement, 'ended', check);
     });
 
-    // The cleanup on timeout
-    const cleanup = () => {
-      this.eventManager_.unlisten(mediaElement, 'timeupdate');
-      this.eventManager_.unlisten(mediaElement, 'ended');
-    };
-
     return this.waitUntilGeneric_(goalName, p, cleanup, mediaElement);
   }