Allow the page to read from the clipboard when handling a paste, as long as the paste was explicitly triggered by the user (i.e. from menu or key binding).
<rdar://problem/63308916>
Created attachment 399567 [details] For EWS (WIP)
Created attachment 399568 [details] For EWS (WIP)
Created attachment 399573 [details] Patch
Committed r261825: <https://trac.webkit.org/changeset/261825> All reviewed patches have been landed. Closing bug and clearing flags on attachment 399573 [details].