[GCM] Pass user states in settings field of MCS login request

BUG=284553
TEST=tests updated
R=fgorski@chromium.org, zea@chromium.org

Review URL: https://codereview.chromium.org/149043004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248232 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248232