Support text track selection in video controls

Source/core/html/shadow/MediaControls.h

Index: Source/core/html/shadow/MediaControls.h
diff --git a/Source/core/html/shadow/MediaControls.h b/Source/core/html/shadow/MediaControls.h
index bb47ef4d1da9a93841e5b01b6d8a9cd11c3c6433..86306ce1f4e615ea910a6211da6304b9bc24b35c 100644
--- a/Source/core/html/shadow/MediaControls.h
+++ b/Source/core/html/shadow/MediaControls.h
@@ -59,6 +59,7 @@ public:
 
     void changedClosedCaptionsVisibility();
     void refreshClosedCaptionsButtonVisibility();
+    void toggleTextTrackList();
 
     void enteredFullscreen();
     void exitedFullscreen();
@@ -123,6 +124,7 @@ private:
     RawPtrWillBeMember<MediaControlMuteButtonElement> m_muteButton;
     RawPtrWillBeMember<MediaControlVolumeSliderElement> m_volumeSlider;
     RawPtrWillBeMember<MediaControlToggleClosedCaptionsButtonElement> m_toggleClosedCaptionsButton;
+    RawPtrWillBeMember<MediaControlTextTrackListElement> m_textTrackList;
     RawPtrWillBeMember<MediaControlFullscreenButtonElement> m_fullScreenButton;
     RawPtrWillBeMember<MediaControlCastButtonElement> m_castButton;
     RawPtrWillBeMember<MediaControlCastButtonElement> m_overlayCastButton;