Bug 1277192 - Correct the association between Cue and TextTrack. r=rillian

MozReview-Commit-ID: 2B2swKL4iM2

--HG--
extra : transplant_source : %C9%C2%EE%A9%2A%FA%80v%7D%B2s%01%B4%A5%B4%98%F2z%06%D0

dom/media/TextTrack.cpp

@@ -153,6 +153,7 @@ TextTrack::RemoveCue(TextTrackCue& aCue, ErrorResult& aRv)
   aCue.SetActive(false);
 
   mCueList->RemoveCue(aCue, aRv);
+  aCue.SetTrack(nullptr);
   if (mTextTrackList) {
     HTMLMediaElement* mediaElement = mTextTrackList->GetMediaElement();
     if (mediaElement) {

testing/web-platform/meta/html/semantics/embedded-content/media-elements/interfaces/TextTrack/addCue.html.ini

@@ -1,5 +0,0 @@
-[addCue.html]
-  type: testharness
-  [TextTrack.addCue(), adding a removed cue to a different track]
-    expected: FAIL
-

testing/web-platform/meta/html/semantics/embedded-content/media-elements/interfaces/TextTrackCue/track.html.ini

@@ -1,8 +0,0 @@
-[track.html]
-  type: testharness
-  [TextTrackCue.track, script-created cue]
-    expected: FAIL
-
-  [TextTrackCue.track, parsed cue]
-    expected: FAIL
-