With http://trac.webkit.org/changeset/104240 I thought it was necessary to make NSTextFieldCells draw with a clear background in order to allow styled text fields. That is not actually necessary…we just had a different bug where isControlStyled() was only checking for styled borders on text fields.
Created attachment 131409 [details]
Fixed with http://trac.webkit.org/changeset/110480
This caused bug 82131.