Hide call to removeDisplayTree in CueTimeline

Source/core/html/track/TextTrack.cpp

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  * Copyright (C) 2011, 2012, 2013 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 155 matching lines @@
 
 void TextTrack::setMode(const AtomicString& mode)
 {
     ASSERT(mode == disabledKeyword() || mode == hiddenKeyword() || mode == showingKeyword());
 
     // On setting, if the new value isn't equal to what the attribute would currently
     // return, the new value must be processed as follows ...
     if (m_mode == mode)
         return;
 
-    // If mode changes to disabled, remove this track's cues from the client
-    // because they will no longer be accessible from the cues() function.
-    if (mode == disabledKeyword() && cueTimeline() && m_cues)
-        cueTimeline()->removeCues(this, m_cues.get());
-
-    if (mode != showingKeyword() && m_cues)
-        for (size_t i = 0; i < m_cues->length(); ++i)
-            m_cues->item(i)->removeDisplayTree();
+    if (m_cues && cueTimeline()) {
+        // If mode changes to disabled, remove this track's cues from the client
+        // because they will no longer be accessible from the cues() function.
+        if (mode == disabledKeyword())
+            cueTimeline()->removeCues(this, m_cues.get());
+        else if (mode != showingKeyword())
+            cueTimeline()->hideCues(this, m_cues.get());
+    }
 
     m_mode = mode;
 
     if (mode != disabledKeyword() && readinessState() == Loaded) {
         if (m_cues && cueTimeline())
             cueTimeline()->addCues(this, m_cues.get());
     }
 
     if (mediaElement())
         mediaElement()->textTrackModeChanged(this);
@@ skipping 294 matching lines @@
 {
     visitor->trace(m_cues);
     visitor->trace(m_activeCues);
     visitor->trace(m_regions);
     visitor->trace(m_trackList);
     TrackBase::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace blink