[Mac] Add interactive App Shim test.

This test creates shims in the user data dir and actually starts them up and
expects them to connect to the IPC socket.

BUG=168080

Review URL: https://codereview.chromium.org/316493002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276368 0039d316-1c4b-4281-b951-d872f2087c98