Reviewed by john

        * editing/pasteboard/subframe-dragndrop-1-expected.checksum: Added.
        * editing/pasteboard/subframe-dragndrop-1-expected.png: Added.
        * editing/pasteboard/subframe-dragndrop-1-expected.txt: Added.
        * editing/pasteboard/subframe-dragndrop-1.html: Added.

WebCore:

        Reviewed by john
        
        <http://bugzilla.opendarwin.org/show_bug.cgi?id=7165>
        TinyMCE: Dragging & dropping content always leaves a copy when editing inside a subframe

        * editing/MoveSelectionCommand.cpp:
        (WebCore::MoveSelectionCommand::MoveSelectionCommand): Set the document
        to the position-to-move-to's document, not the fragment's document.  The 
        fragment's document is the document used to create the fragment and is irrelavant.

WebKit:

        Reviewed by john
        
        <http://bugzilla.opendarwin.org/show_bug.cgi?id=7165>
        TinyMCE: Dragging & dropping content always leaves a copy when editing inside a subframe
        
        The top level WebHTMLView is responsible for performing dragging operations, but
        the inner view, the view that holds the drag caret, should be consulted to determine
        if the drag is a move drag.

        * WebCoreSupport/WebFrameBridge.m:
        (-[WebFrameBridge startDraggingImage:at:operation:event:sourceIsDHTML:DHTMLWroteData:]):
        * WebKit.xcodeproj/project.pbxproj:
        * WebView/WebHTMLView.m:
        (-[NSArray dragImage:at:offset:event:pasteboard:source:slideBack:]): Don't set initatedDrag here, because
        it's only the top level WebHTMLView that performs this operation.
        (-[WebHTMLView _setInitiatedDrag:]): Added.
        (-[WebHTMLView _initiatedDrag]): Ditto.
        (-[WebHTMLView _canProcessDragWithDraggingInfo:]): Ask the innerView if it initiated the drag,
        not the top level view.
        (-[WebHTMLView _isMoveDrag]): The top level view asks the innerView if it should perform
        a move drag, so don't ASSERT _isTopHTMLView.
        (-[WebHTMLView draggingUpdatedWithDraggingInfo:actionMask:]): Ask the innerView if _isMoveDrag.
        (-[WebHTMLView concludeDragForDraggingInfo:actionMask:]): Ditto.
        * WebView/WebHTMLViewInternal.h: Added two private SPI so that
        the top level WebHTMLView can set and get the initiatedDrag BOOL.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@16500 268f45cc-cd09-0410-ab3c-d52691b4dbfc