Add test for google_apis::RequestSender that covers reauthentication code path.

BUG=161207

Review URL: https://codereview.chromium.org/26444005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228192 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228192