https://bugs.webkit.org/show_bug.cgi?id=76677

    Reviewed by Simon Fraser.

    Make sure a press targets an element's center point.

    * accessibility/press-targets-center-point-expected.txt: Added.
    * accessibility/press-targets-center-point.html: Added.

    Set the coordinates of a simulated press equal to the center of the target
    element when the simulated press does not have a related mouse event.

    Test: accessibility/press-targets-center-point.html

    * dom/Element.cpp:
    (WebCore::Element::clientRect):
    (WebCore::Element::screenRect):
    * dom/Element.h:
    * dom/EventDispatcher.cpp:
    (WebCore::EventDispatcher::dispatchSimulatedClick):
    * dom/MouseEvent.cpp:
    (WebCore::SimulatedMouseEvent::create):
    (WebCore::SimulatedMouseEvent::SimulatedMouseEvent):
    * dom/MouseEvent.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@160032 268f45cc-cd09-0410-ab3c-d52691b4dbfc