QUIC - minor cleanup changes found while merging chromium code into
internal code.

R=rch@chromium.org

Review URL: https://codereview.chromium.org/111323006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241129 0039d316-1c4b-4281-b951-d872f2087c98
Polish VK show/hide animation

This CL did:
1. add opacity animation for VK when show/hide
2. reduce animation time to 100 ms


BUG=327462

Review URL: https://codereview.chromium.org/114803004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241130 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241129
SVN changes up to revision 241130