Reviewed by Martin Robinson.

        [GTK] Implement increment() and decrement() functions in DRT's AccessibilityUIElement
        https://bugs.webkit.org/show_bug.cgi?id=58039

        Implemented missing functions in GTK's DRT.

        * WebCoreSupport/DumpRenderTreeSupportGtk.h:
        * WebCoreSupport/DumpRenderTreeSupportGtk.cpp:
        (modifyAccessibilityValue): Helper function to increment or decrement
        the current value for an object through the AccessibilityObject's API.
        (DumpRenderTreeSupportGtk::incrementAccessibilityValue): New function,
        to be used from GTK's DRT.
        (DumpRenderTreeSupportGtk::decrementAccessibilityValue): Ditto.
2011-04-08  Mario Sanchez Prada  <msanchez@igalia.com>

        Reviewed by Martin Robinson.

        [GTK] Implement increment() and decrement() functions in DRT's AccessibilityUIElement
        https://bugs.webkit.org/show_bug.cgi?id=58039

        Implement missing functions in GTK's DRT.

        * DumpRenderTree/gtk/AccessibilityUIElementGtk.cpp:
        (AccessibilityUIElement::increment): Implemented.
        (AccessibilityUIElement::decrement): Implemented.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@83271 268f45cc-cd09-0410-ab3c-d52691b4dbfc