Implement setPrivateBrowsingEnabled in window.internals and remove duplicated code from WebKitTestRunner and DumpRenderTree.
Created attachment 143606 [details] Patch
Comment on attachment 143606 [details] Patch Attachment 143606 [details] did not pass gtk-ews (gtk): Output: http://queues.webkit.org/results/12772280
Same as https://bugs.webkit.org/show_bug.cgi?id=87149#c5
Comment on attachment 143606 [details] Patch Attachment 143606 [details] did not pass mac-ews (mac): Output: http://queues.webkit.org/results/12774291
Created attachment 143629 [details] Patch
Comment on attachment 143629 [details] Patch Attachment 143629 [details] did not pass win-ews (win): Output: http://queues.webkit.org/results/12769313
*** This bug has been marked as a duplicate of bug 85034 ***
Comment on attachment 143629 [details] Patch Clearing review flag, since this has been decided wontfix in original.