Mojo: Make mojob build only mojo.

R=darin
NOTRY=True

Review URL: https://codereview.chromium.org/56973010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233006 0039d316-1c4b-4281-b951-d872f2087c98
cros: Don't load Genius help app in tests

This breaks some tests in official builds.

BUG=None
TEST=browser_tests ExtensionProcessManagerBrowserTest
R=dpolukhin@chromium.org, yoz@chromium.org

Review URL: https://codereview.chromium.org/56003006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233008 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233008