The compositor debug borders (--show-debug-borders) are not drawn with contents scale applied, so they do not coincide with their respective layers if contents scale != 1.
Created attachment 124801 [details] Patch
Comment on attachment 124801 [details] Patch Hmm, guess this is why http://trac.webkit.org/export/106381/trunk/LayoutTests/compositing/color-matching/image-color-matching.html looks so cracked out with layer borders on :) R=me
Comment on attachment 124801 [details] Patch Clearing flags on attachment: 124801 Committed r106406: <http://trac.webkit.org/changeset/106406>
All reviewed patches have been landed. Closing bug.