DEFAULT keyword wasn't removed on Bug 72815 as below, WEBKIT_OPTION_DEFINE(ENABLE_DRAG_SUPPORT "Toggle Drag Support" DEFAULT OFF) It seems to me it is unneeded anymore.
Created attachment 139962 [details] Patch
Comment on attachment 139962 [details] Patch OK.
Comment on attachment 139962 [details] Patch Clearing flags on attachment: 139962 Committed r115945: <http://trac.webkit.org/changeset/115945>
All reviewed patches have been landed. Closing bug.