Remove TextTrackCueBox

Source/core/html/track/TextTrackCue.h

Index: Source/core/html/track/TextTrackCue.h
diff --git a/Source/core/html/track/TextTrackCue.h b/Source/core/html/track/TextTrackCue.h
index 7feb45d9a8cf98213c40ae826f4245fcb4771bfd..706cbf87902bdc44a1376827996c78747aa2dcc3 100644
--- a/Source/core/html/track/TextTrackCue.h
+++ b/Source/core/html/track/TextTrackCue.h
@@ -38,25 +38,7 @@
 
 namespace WebCore {
 
-class Document;
 class ExceptionState;
-class TextTrackCue;
-
-// ----------------------------
-
-class TextTrackCueBox : public HTMLDivElement {
-public:
-    static const AtomicString& textTrackCueBoxShadowPseudoId()
-    {
-        DEFINE_STATIC_LOCAL(const AtomicString, trackDisplayBoxShadowPseudoId, ("-webkit-media-text-track-display", AtomicString::ConstructFromLiteral));
-        return trackDisplayBoxShadowPseudoId;
-    }
-
-protected:
-    TextTrackCueBox(Document&);
-};
-
-// ----------------------------
 
 class TextTrackCue : public RefCounted<TextTrackCue>, public EventTargetWithInlineData {
     REFCOUNTED_EVENT_TARGET(TextTrackCue);