Some internal editing clients need the ability to withhold a subset of a session's item providers from being handled by the page on drop. Currently, this results in WebItemProviderPasteboard being unable to load content, due to WebItemProviderPasteboard's list of preferred type identifiers to load not matching up with its list of item providers.
Created attachment 312928 [details] Patch
<rdar://problem/32777720>
Created attachment 312932 [details] Rebase on master
Created attachment 312942 [details] Patch
Comment on attachment 312942 [details] Patch Much nicer!
Created attachment 312990 [details] Patch for landing
Comment on attachment 312990 [details] Patch for landing Clearing flags on attachment: 312990 Committed r218343: <http://trac.webkit.org/changeset/218343>