SharedMemory release build hardening. Making a named memory entry can succeed but give a memory object size smaller than the size requested. This is an error for us and should be treated as a failure to create the memory. <rdar://problem/13546860>
Note, there's already an ASSERT to this effect, but it needs to be handled in release builds also.
Created attachment 195995 [details] Patch v1
http://trac.webkit.org/changeset/147342