It currently uses the release lib (and thus dll) when compiling in DebugSuffix mode.
Created attachment 210529 [details]
Comment on attachment 210529 [details]
I think there are a couple of more places that have to be updated to have the full WebKit stack link properly. I'm working on this now for a different reason, and will post another patch related to this one. I think we still link against AVFoundationCF.dll, rather than AVFoundationCF_debug.dll, for example.
When using this change, we should also include http://trac.webkit.org/changeset/155130, as this corrects the AVFoundationCF linkage.