Adding unit test to check multi user functionality of the shelf for V2 applications


BUG=312455
TEST=unittest

Review URL: https://codereview.chromium.org/61293002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233641 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233641