Need to disable FakeSYSVSHM when sandboxing is not enabled
https://bugs.webkit.org/show_bug.cgi?id=120182
<rdar://problem/14814461>

Patch by Simon Cooper <scooper@apple.com> on 2013-08-22
Reviewed by Alexey Proskuryakov.

When not in a sandbox do not enable the FakeSYSVSHIM. This
allows LocalConnection to work when Flash Player is run in
"Unsafe Mode".

* PluginProcess/mac/PluginProcessShim.mm:
(WebKit::shim_disabled):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154473 268f45cc-cd09-0410-ab3c-d52691b4dbfc