linux aura: Allow setting window-role hint for X11 window managers.

Some window managers allow certain rules for window-positioning etc. based on
the 'role' of the window. So make sure this 'role' is set for the created
windows.

BUG=319548
R=erg@chromium.org, sky@chromium.org

Review URL: https://codereview.chromium.org/60703004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235538 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235538
Fix location of supervised user token file on non-chromeos.


BUG=312751
R=bauerb@chromium.org

Review URL: https://codereview.chromium.org/62163002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235539 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235539