Eliminate calls to TextTrackCue::setIsActive outside of CueTimeline

Source/core/html/track/TextTrackCueList.cpp

Index: Source/core/html/track/TextTrackCueList.cpp
diff --git a/Source/core/html/track/TextTrackCueList.cpp b/Source/core/html/track/TextTrackCueList.cpp
index 40052b9b4aef97ea42f7f0571ba537dd3492b12b..4b43f829d78d53879ac56dc4d5b7eca883d226ad 100644
--- a/Source/core/html/track/TextTrackCueList.cpp
+++ b/Source/core/html/track/TextTrackCueList.cpp
@@ -128,9 +128,6 @@ void TextTrackCueList::updateCueIndex(TextTrackCue* cue)
     if (!remove(cue))
         return;
 
-    cue->setIsActive(false);
-    cue->removeDisplayTree();
-
     // FIXME: If moving the cue such that its index in list increases, then
     // what happens with the cached index on cues in the range [oldIndex,
     // newIndex)? (Some of the indices will be "safe", but there'll be a risk