Revert 200486 "Include full user email in the response of Challe..."
This revert is speculative. After r200486 committed, ExtensionApiTest started to
fail consistently. This change seems to be the only one related to extensions
API.
> Include full user email in the response of ChallengeUserKey().
>
> BUG=chromium:240785
> TEST=unit_tests
>
> Review URL: https://chromiumcodereview.appspot.com/
15037003
TBR=davidyu@chromium.org
Review URL: https://codereview.chromium.org/
15085028
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@200549 0039d316-1c4b-4281-b951-d872f2087c98