Reviewed by Darin.

        - test for http://bugs.webkit.org/show_bug.cgi?id=12344
          NativeListBox: item hit testing does not account for top padding and border

        * fast/forms/listbox-selection-2-expected.checksum: Added.
        * fast/forms/listbox-selection-2-expected.png: Added.
        * fast/forms/listbox-selection-2-expected.txt: Added.
        * fast/forms/listbox-selection-2.html: Added.

WebCore:

        Reviewed by Darin.

        - fix http://bugs.webkit.org/show_bug.cgi?id=12344
          NativeListBox: item hit testing does not account for top padding and border

        Test: fast/forms/listbox-selection-2.html

        * rendering/RenderListBox.cpp:
        (WebCore::RenderListBox::numVisibleItems): Changed height() to contentHeight()
        since items are visible only in the content box.
        (WebCore::RenderListBox::listIndexAtOffset): Adjusted for vertical padding and
        borders. Changed to return -1 instead of the last item's index if the given offset
        is below the last item.
        (WebCore::RenderListBox::autoscroll): Adjusted for vertical padding and borders.
        (WebCore::RenderListBox::controlClipRect): Changed to return the content box since
        items should not spill into the padding box. This change is the reason the test
        generates pixel results.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@19037 268f45cc-cd09-0410-ab3c-d52691b4dbfc