Reviewed by Adam Roben.

        https://bugs.webkit.org/show_bug.cgi?id=24731
        And
        rdar://problem/5015961
        
        Implements support for DHTML drag-and-drop operations (i.e. ondragstart, ondragend)
        in the Windows build so that it conforms to the Mac OS X build. Hence, dropEffect is
        correctly set.
        
        The WebView and WebDropSource drag-and-drop functions, as called by function
        DoDragDrop in its event loop, neither used the drop effect as specified by
        event.dataTransfer.dropEffect nor respected event.dataTransfer.effectsAllowed.
        Instead, these functions defaulted to some hardcoded drop effect and set of
        allowed drop effects, respectively.

        Tests: fast/events/drag-and-drop.html

        * WebCoreSupport/WebDragClient.cpp:
        (WebDragClient::startDrag):
        * WebDropSource.cpp:
        (WebDropSource::QueryContinueDrag): Moved call to EventHandler::dragSourceEndedAt
        into method WebDragClient::startDrag.
        * WebDropSource.h:
        * WebView.cpp:
        (WebView::keyStateToDragOperation): Fixes <rdar://problem/5015961>. Determines
        appropriate drop effect from state of keyboard and allowed effects
        m_page->dragController()->sourceDragOperation().
        (WebView::DragEnter):
        (WebView::DragOver):
        (WebView::Drop):
        * WebView.h:
2009-10-15  Daniel Bates  <dbates@webkit.org>

        Reviewed by Adam Roben.

        https://bugs.webkit.org/show_bug.cgi?id=24731
        And
        rdar://problem/5015961
        
        Tests that DHTML drag-and-drop works correctly.
        
        Note, this test fails when effectAllowed == "uninitialized" because 
        this effect has not been implemented yet (see bug #30291).

        * fast/events/drag-and-drop-expected.txt: Added.
        * fast/events/drag-and-drop.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@49651 268f45cc-cd09-0410-ab3c-d52691b4dbfc