Upon exiting a WKContentView, the dropSession is not cleared out. If the drag session re-enters the WKWebView, a *different* UIDropSession is sent to the drop delegate, causing us to bail in -dropInteraction:canHandleSession: and not handle the drag. To fix this, we need to clear out dropSession when the drag session exits the view.
<rdar://problem/32957100>
Created attachment 313886 [details] Patch
Comment on attachment 313886 [details] Patch Clearing flags on attachment: 313886 Committed r218834: <http://trac.webkit.org/changeset/218834>
All reviewed patches have been landed. Closing bug.