[Qt] Zoom out on second double-tap.

[Qt] Zoom out on second double-tap.
https://bugs.webkit.org/show_bug.cgi?id=84145

Patch by Allan Sandfeld Jensen <allan.jensen@nokia.com> on 2012-04-17
Reviewed by Simon Hausmann.

* UIProcess/qt/QtViewportInteractionEngine.cpp:
(WebKit::QtViewportInteractionEngine::QtViewportInteractionEngine):
(WebKit::QtViewportInteractionEngine::zoomToAreaGestureEnded):
(WebKit::QtViewportInteractionEngine::pinchGestureStarted):
* UIProcess/qt/QtViewportInteractionEngine.h:
(QtViewportInteractionEngine):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114370 268f45cc-cd09-0410-ab3c-d52691b4dbfc