Make GetShowState() private

ash code should use WindowState::GetStateType() to check window state instead (from now on).

BUG=None

Review URL: https://codereview.chromium.org/177213017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253976 0039d316-1c4b-4281-b951-d872f2087c98
Make the top bar semitransparent when in immersive fullscreen

BUG=346062
TEST=Manual, see bug

Review URL: https://codereview.chromium.org/176523002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253977 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253977