Give Unique StringImpls a meaningful data pointer
Created attachment 219000 [details] Patch
Comment on attachment 219000 [details] Patch r=me, but add a comment in the code that we expect m_buffer to be null. If we change StringImpl in the future it will be easier to see why you're doing this without tracking down the change set / bug.
Committed r160453: <http://trac.webkit.org/changeset/160453>