Start separating the text track container from the media controls

Source/core/html/shadow/MediaControlElements.h

Index: Source/core/html/shadow/MediaControlElements.h
diff --git a/Source/core/html/shadow/MediaControlElements.h b/Source/core/html/shadow/MediaControlElements.h
index 1b3d5a60fed001b43932d89dcf4d2ac3df7e86e2..66cb49b1feb72a88ae314e4da98b5b9efe58e24e 100644
--- a/Source/core/html/shadow/MediaControlElements.h
+++ b/Source/core/html/shadow/MediaControlElements.h
@@ -236,25 +236,6 @@ private:
     explicit MediaControlCurrentTimeDisplayElement(MediaControls&);
 };
 
-// ----------------------------
-
-class MediaControlTextTrackContainerElement final : public MediaControlDivElement {
-public:
-    static PassRefPtrWillBeRawPtr<MediaControlTextTrackContainerElement> create(MediaControls&);
-
-    void updateDisplay();
-    void updateSizes();
-
-private:
-    explicit MediaControlTextTrackContainerElement(MediaControls&);
-
-    virtual LayoutObject* createLayoutObject(const LayoutStyle&) override;
-
-    IntRect m_videoDisplaySize;
-    float m_fontSize;
-};
-
-
 } // namespace blink
 
 #endif // MediaControlElements_h