Fix public session sign in.

Don't force online auth type for them.

BUG=346308

Review URL: https://codereview.chromium.org/178083002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253112 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253112
Removes #ash-multiple-snap-window-widths flag

BUG=343276
TEST=ash_unittests --gtest_filter=*Snap*

Review URL: https://codereview.chromium.org/171003005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253115 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253115