There's no way to test the gesture tap on WTR because the code on QtWebPageEventHandler::doneWithTouchEvent relies on a instance of QtViewportHandler and such instance doesn't exist because WTR runs on "desktop mode".
Created attachment 156184 [details]
As far as I remember componentComplete is only triggered in QML, so in C++ unless WTR creates a WebView component dinamically this codepath won't be triggered so the viewport handler will still be null there, but I might be wrong.
Comment on attachment 156184 [details]
Clearing flags on attachment: 156184
Committed r124625: <http://trac.webkit.org/changeset/124625>
All reviewed patches have been landed. Closing bug.