Support text track selection in video controls

third_party/WebKit/Source/core/html/track/TextTrack.h

 /*
  * 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:
  * 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
@@ skipping 38 matching lines @@
     DEFINE_WRAPPERTYPEINFO();
     USING_GARBAGE_COLLECTED_MIXIN(TextTrack);
 public:
     static TextTrack* create(const AtomicString& kind, const AtomicString& label, const AtomicString& language)
     {
         return new TextTrack(kind, label, language, emptyAtom, AddTrack);
     }
     ~TextTrack() override;
 
     virtual void setTrackList(TextTrackList*);
-    TextTrackList* trackList() { return m_trackList; }
+    TextTrackList* trackList() const { return m_trackList; }
 
     void setKind(const AtomicString&) override;
 
     static const AtomicString& subtitlesKeyword();
     static const AtomicString& captionsKeyword();
     static const AtomicString& descriptionsKeyword();
     static const AtomicString& chaptersKeyword();
     static const AtomicString& metadataKeyword();
     static bool isValidKindKeyword(const String&);
 
@@ skipping 25 matching lines @@
     void cueDidChange(TextTrackCue*);
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(cuechange);
 
     enum TextTrackType { TrackElement, AddTrack, InBand };
     TextTrackType trackType() const { return m_trackType; }
 
     int trackIndex();
     void invalidateTrackIndex();
 
-    bool isRendered();
+    bool isRendered() const;
+    bool canBeRendered() const;
     int trackIndexRelativeToRenderedTracks();
 
     bool hasBeenConfigured() const { return m_hasBeenConfigured; }
     void setHasBeenConfigured(bool flag) { m_hasBeenConfigured = flag; }
 
     virtual bool isDefault() const { return false; }
 
     void removeAllCues();
 
     // EventTarget methods
@@ skipping 27 matching lines @@
     int m_trackIndex;
     int m_renderedTrackIndex;
     bool m_hasBeenConfigured;
 };
 
 DEFINE_TRACK_TYPE_CASTS(TextTrack, WebMediaPlayer::TextTrack);
 
 } // namespace blink
 
 #endif // TextTrack_h