The caching of String's is8Bit() and characters8()/characters16() on RenderText looks like a premature optimization. We can save memory by going through m_text.*() instead. I see no measurable difference on PLT here.
Created attachment 187451 [details] Patch
Comment on attachment 187451 [details] Patch Clearing flags on attachment: 187451 Committed r142398: <http://trac.webkit.org/changeset/142398>
All reviewed patches have been landed. Closing bug.