Merge pull request #8321 from w3c/sync_16a0446867e17d76e695afe676201272d05286d0

Increase timeout for tone events in RTCDTMFSender-helper.js;
diff --git a/webrtc/RTCDTMFSender-helper.js b/webrtc/RTCDTMFSender-helper.js
index b66c4ae..97bb6f9 100644
--- a/webrtc/RTCDTMFSender-helper.js
+++ b/webrtc/RTCDTMFSender-helper.js
@@ -76,8 +76,8 @@
         const now = Date.now();
         const duration = now - lastEventTime;
 
-        assert_approx_equals(duration, expectedDuration, 150,
-          `Expect tonechange event for "${tone}" to be fired approximately after ${expectedDuration} seconds`);
+        assert_approx_equals(duration, expectedDuration, 250,
+          `Expect tonechange event for "${tone}" to be fired approximately after ${expectedDuration} milliseconds`);
 
         lastEventTime = now;