Prevent 'removetrack' events from firing when all inband text tracks are removed.

LayoutTests/media/track/track-remove-track-expected.txt

Index: LayoutTests/media/track/track-remove-track-expected.txt
diff --git a/LayoutTests/media/track/track-remove-track-expected.txt b/LayoutTests/media/track/track-remove-track-expected.txt
index c8e4fcd89ed5c073215ef6e84a980aa4c736acf4..13cf72cc5f755ab7f9b90964e203a2b25a801b88 100644
--- a/LayoutTests/media/track/track-remove-track-expected.txt
+++ b/LayoutTests/media/track/track-remove-track-expected.txt
@@ -1,15 +1,4 @@
-Tests that the 'removetrack' event is fired when a TextTrack is removed.
-
-** Test a TextTrack created for a <track> element.
-RUN(trackElement = document.createElement('track'))
-RUN(video.appendChild(trackElement))
-RUN(trackElement.src = 'captions-webvtt/tc004-webvtt-file.vtt')
-RUN(trackElement.track.mode = 'hidden')
-EXPECTED (video.textTracks.length == '1') OK
-EVENT(removetrack)
-EXPECTED (event.target == '[object TextTrackList]') OK
-EXPECTED (event instanceof window.TrackEvent == 'true') OK
-EXPECTED (event.track == '[object TextTrack]') OK
-
-END OF TEST
-
+This is a testharness.js-based test.
+PASS Tests that the 'removetrack' event is fired when an out-of-band TextTrack is removed. 
+PASS Tests that the 'removetrack' event is NOT fired for inband TextTrack on a failed load. 
+Harness: the test ran to completion.