Pixel test support isn't implemented in WebKitTestRunner on Windows. We should fix that!
Created attachment 86143 [details] WIP patch (won't build on Mac)
Created attachment 86193 [details] Patch
Committed r81494: <http://trac.webkit.org/changeset/81494>
http://trac.webkit.org/changeset/81494 might have broken Windows Release (Build) and Windows Debug (Build)