Remove unused show/hideTextTrackDisplay()

BUG=448795

Review URL: https://codereview.chromium.org/951253002

git-svn-id: svn://svn.chromium.org/blink/trunk@190733 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/html/shadow/MediaControls.cpp

@@ -528,20 +528,6 @@ void MediaControls::createTextTrackDisplay()
     m_overlayEnclosure->insertBefore(textDisplayContainer.release(), m_overlayEnclosure->firstChild());
 }
 
-void MediaControls::showTextTrackDisplay()
-{
-    if (!m_textDisplayContainer)
-        createTextTrackDisplay();
-    m_textDisplayContainer->show();
-}
-
-void MediaControls::hideTextTrackDisplay()
-{
-    if (!m_textDisplayContainer)
-        createTextTrackDisplay();
-    m_textDisplayContainer->hide();
-}
-
 void MediaControls::updateTextTrackDisplay()
 {
     if (!m_textDisplayContainer)

third_party/WebKit/Source/core/html/shadow/MediaControls.h

@@ -101,8 +101,6 @@ private:
     void tryShowOverlayCastButton();
 
     void createTextTrackDisplay();
-    void showTextTrackDisplay();
-    void hideTextTrackDisplay();
 
     // Node
     virtual bool isMediaControls() const override { return true; }