Reviewed by Eric Seidel.

        Initialize DataTransfer's effectAllowed and dropEffect properties correctly
        according to HTML5 spec (sec. 7.9.2-7.9.3).
        https://bugs.webkit.org/show_bug.cgi?id=26700

        * fast/events/drag-dropeffect-expected.txt: Added.
        * fast/events/drag-dropeffect.html: Added.
2009-09-09  Jens Alfke  <snej@chromium.org>

        Reviewed by Eric Seidel.

        Initialize DataTransfer's effectAllowed and dropEffect properties correctly
        according to HTML5 spec (sec. 7.9.2-7.9.3).
        https://bugs.webkit.org/show_bug.cgi?id=26700
        - At the start of a drag operation, the value of effectAllowed should be
          the string "uninitialized".
        - At end of dragstart handler, if effectAllowed hasn't been set yet, it
          should be set to "copy".
        - on dragenter and dragover event, dropEffect should be initialized to a
          default value based on the value of effectAllowed.
        - at end of dragenter and dragover the dropEffect should be set to "none"
          if the value set by the handler doesn't match the effectAllowed.
        - on dragleave event, dropEffect should be "none".
        - on drop event, dropEffect should be the previously negotiated value.

        Test: fast/events/drag-dropeffect.html

        * WebCore.base.exp:
            Added a parameter to EventHandler::dragSourceMovedTo.
        * dom/Clipboard.cpp:
        (WebCore::Clipboard::Clipboard):
            Initialize m_effectAllowed to "uninitialized".
        (WebCore::Clipboard::sourceOperation):
            Treat "uninitialized" as meaning no value has been set.
        * page/DragController.cpp:
        (WebCore::DragController::DragController):
            Initialize new member m_destinationDragOperation.
        (WebCore::DragController::dragExited):
            Set m_destinationDragOperation to none on dragExit.
        (WebCore::DragController::performDrag):
            Set m_destinationDragOperation to current dropEffect.
        (WebCore::DragController::dragEnteredOrUpdated):
            Make sure to clear the operation if drag source doesn't allow it.
        (WebCore::DragController::tryDHTMLDrag):
            Set a default value for the dst drag op before sending dragEnter/Over.
        (WebCore::DragController::startDrag):
            Clear m_destinationDragOperation at start of drag.
        * page/DragController.h:
        (WebCore::DragController::destinationDragOperation):
            Added new member m_destinationDragOperation, and its public getter.
        * page/EventHandler.cpp:
        (WebCore::EventHandler::updateDragAndDrop):
            dropEffect should be 'none' during dropleave handler, per spec.
        (WebCore::EventHandler::dragSourceMovedTo):
            Added DragOperation parameter, so the handler sees the current dropEffect.
        (WebCore::EventHandler::handleDrag):
            Assume DragOperationEvery for non-DHTML drags.
        * page/EventHandler.h:
            Added DragOperation parameter to dragSourceMovedTo().
2009-09-09  Jens Alfke  <snej@chromium.org>

        Reviewed by Eric Seidel.

        Initialize DataTransfer's effectAllowed and dropEffect properties correctly
        according to HTML5 spec (sec. 7.9.2-7.9.3).
        https://bugs.webkit.org/show_bug.cgi?id=26700

        * WebView/WebFrame.mm:
        (-[WebFrame _dragSourceMovedTo:]):
            Pass current drag operation (if known) to EventHandler::dragSourceMovedTo().

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@48229 268f45cc-cd09-0410-ab3c-d52691b4dbfc