DTMFSender-ontonechange is no longer flaky

With the implementation of transceiver.stop(), this test is no longer
flaky, and isn't believed to time out.

Bug: chromium:923244, chromium:893112, chromium:980879
Change-Id: I60e691ed84a219a26980a6c2ba4c3f2294e2bbac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2410070
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Reviewed-by: Henrik Boström <hbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806970}

third_party/blink/web_tests/TestExpectations

@@ -5354,8 +5354,6 @@ crbug.com/719023 media_capabilities/encodingInfo-avc1.html [ Pass Failure ]
 # Sheriff 2019-01-07
 crbug.com/919587 [ Linux ] virtual/threaded/fast/idle-callback/idle_periods.html [ Pass Failure ]
 
-# WebRTC Unified Plan
-crbug.com/923244 external/wpt/webrtc/RTCDTMFSender-ontonechange.https.html [ Failure Pass Crash Timeout ]
 # WebRTC Plan B
 crbug.com/920979 virtual/webrtc-wpt-plan-b/external/wpt/webrtc/RTCTrackEvent-fire.html [ Timeout ]
 

third_party/blink/web_tests/external/wpt/webrtc/RTCDTMFSender-ontonechange.https-expected.txt

 This is a testharness.js-based test.
-Harness Error. harness_status.status = 1 , harness_status.message = Uncaught TypeError: transceiver.stop is not a function
 PASS insertDTMF() with default duration and intertoneGap should fire tonechange events at the expected time
 PASS insertDTMF() with explicit duration and intertoneGap should fire tonechange events at the expected time
 PASS insertDTMF('') should not fire any tonechange event, including for '' tone
 PASS insertDTMF() with duration less than 40 should be clamped to 40
 PASS insertDTMF() with interToneGap less than 30 should be clamped to 30
 PASS insertDTMF with comma should delay next tonechange event for a constant 2000ms
-FAIL insertDTMF() with transceiver stopped in the middle should stop future tonechange events from firing assert_greater_than: More tonechange event is fired than expected expected a number greater than 0 but got 0
+PASS insertDTMF() with transceiver stopped in the middle should stop future tonechange events from firing
 PASS Calling insertDTMF() in the middle of tonechange events should cause future tonechanges to be updated to new tones
 PASS Calling insertDTMF() multiple times in the middle of tonechange events should cause future tonechanges to be updated the last provided tones
 PASS Calling insertDTMF('') in the middle of tonechange events should stop future tonechange events from firing
-FAIL Setting transceiver.currentDirection to recvonly in the middle of tonechange events should stop future tonechange events from firing Failed to execute 'insertDTMF' on 'RTCDTMFSender': The 'canInsertDTMF' attribute is false: this sender cannot send DTMF.
+PASS Setting transceiver.currentDirection to recvonly in the middle of tonechange events should stop future tonechange events from firing
 PASS Tone change event constructor works
 PASS Tone change event with unexpected name should not crash
+FAIL Tone change event init optional parameters Failed to construct 'RTCDTMFToneChangeEvent': 2 arguments required, but only 1 present.
 Harness: the test ran to completion.