We have the same checks if two BasicShape objects can be blended twice. Refactor the code and add a canBlend method in BasicShape that combined the check.
Created attachment 174268 [details] Patch
Comment on attachment 174268 [details] Patch The double-negatives are a bit confusing. But this looks right.
Committed r134679: <http://trac.webkit.org/changeset/134679>