Mojo: Make C API test work on MSVS before 2013.

R=davemoore@chromium.org

Review URL: https://codereview.chromium.org/136363004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246183 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246183