It's enough to restore the CompositeOperator after drawing.
Created attachment 76535 [details] Proposed patch
Comment on attachment 76535 [details] Proposed patch I trust you on this! :-)
The commit-queue encountered the following flaky tests while processing attachment 76535 [details]: fast/workers/storage/use-same-database-in-page-and-workers.html bug 50995 (author: dumi@chromium.org) fast/history/history-subframe-with-name.html bug 51039 (author: mihaip@chromium.org) The commit-queue is continuing to process your patch.
Comment on attachment 76535 [details] Proposed patch Clearing flags on attachment: 76535 Committed r74035: <http://trac.webkit.org/changeset/74035>
All reviewed patches have been landed. Closing bug.