Remove MediaControls::showVolumeSlider()

This is a remnant from WebKit when there was a volume slider container
that could be shown and hidden. What remains is essentially dead code,
because at most it shows the slider when m_mediaController->hasAudio(),
but MediaControls::reset() already does that.

BUG=341813

Review URL: https://codereview.chromium.org/176883020

git-svn-id: svn://svn.chromium.org/blink/trunk@168452 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -286,7 +286,6 @@ const AtomicString& MediaControlOverlayEnclosureElement::shadowPseudoId() const
 
 MediaControlPanelMuteButtonElement::MediaControlPanelMuteButtonElement(Document& document, MediaControls* controls)
     : MediaControlMuteButtonElement(document, MediaMuteButton)
-    , m_controls(controls)
 {
 }
 
@@ -300,14 +299,6 @@ PassRefPtr<MediaControlPanelMuteButtonElement> MediaControlPanelMuteButtonElemen
     return button.release();
 }
 
-void MediaControlPanelMuteButtonElement::defaultEventHandler(Event* event)
-{
-    if (event->type() == EventTypeNames::mouseover)
-        m_controls->showVolumeSlider();
-
-    MediaControlMuteButtonElement::defaultEventHandler(event);
-}
-
 const AtomicString& MediaControlPanelMuteButtonElement::shadowPseudoId() const
 {
     DEFINE_STATIC_LOCAL(AtomicString, id, ("-webkit-media-controls-mute-button", AtomicString::ConstructFromLiteral));

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

@@ -110,9 +110,6 @@ private:
     explicit MediaControlPanelMuteButtonElement(Document&, MediaControls*);
 
     virtual const AtomicString& shadowPseudoId() const OVERRIDE;
-    virtual void defaultEventHandler(Event*) OVERRIDE;
-
-    MediaControls* m_controls;
 };
 
 // ----------------------------

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

@@ -303,14 +303,6 @@ void MediaControls::updateCurrentTimeDisplay()
     m_currentTimeDisplay->setCurrentValue(now);
 }
 
-void MediaControls::showVolumeSlider()
-{
-    if (!m_mediaController->hasAudio())
-        return;
-
-    m_volumeSlider->show();
-}
-
 void MediaControls::changedMute()
 {
     m_panelMuteButton->changedMute();

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

@@ -60,7 +60,6 @@ public:
     virtual void playbackStopped();
 
     void updateCurrentTimeDisplay();
-    void showVolumeSlider();
 
     void changedMute();
     void changedVolume();