Hook up Android closed captions 'enabled' setting to Blink

Source/core/html/track/TextTrackList.cpp

 /*
  * Copyright (C) 2011, 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 301 matching lines @@
     // media element, then the user agent must remove the track element's
     // corresponding text track from the media element's list of text tracks,
     // and then queue a task to fire a trusted event with the name removetrack,
     // that does not bubble and is not cancelable, and that uses the TrackEvent
     // interface, with the track attribute initialized to the text track's
     // TextTrack object, at the media element's textTracks attribute's
     // TextTrackList object.
     scheduleTrackEvent(EventTypeNames::removetrack, track);
 }
 
+bool TextTrackList::hasShowingTracks()
+{
+    for (unsigned i = 0; i < length(); ++i) {
+        if (item(i)->mode() == TextTrack::showingKeyword())
+            return true;
+    }
+    return false;
+}
+
 HTMLMediaElement* TextTrackList::owner() const
 {
     return m_owner;
 }
 
 DEFINE_TRACE(TextTrackList)
 {
     visitor->trace(m_owner);
     visitor->trace(m_asyncEventQueue);
     visitor->trace(m_addTrackTracks);
     visitor->trace(m_elementTracks);
     visitor->trace(m_inbandTracks);
     EventTargetWithInlineData::trace(visitor);
 }