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
4 files changed
tree: c4a7fc5764f62ff09108c3e4b077e7e4ab058705
  1. third_party/