sourceOperation   105 Source/core/clipboard/Clipboard.h     DragOperation sourceOperation() const;
sourceOperation    73 Source/web/DragClientImpl.cpp     WebDragOperationsMask dragOperationMask = static_cast<WebDragOperationsMask>(clipboard->sourceOperation());
sourceOperation   748 Source/web/WebPluginContainerImpl.cpp     WebDragOperationsMask dragOperationMask = static_cast<WebDragOperationsMask>(clipboard->sourceOperation());