Timeline's frame mode currently displays all events before first didBeginFrame() call as independent events. This may appear confusing, so let's regard first event we receive as a frame start marker.
Created attachment 145570 [details] Patch
Comment on attachment 145570 [details] Patch lgtm
Comment on attachment 145570 [details] Patch Clearing flags on attachment: 145570 Committed r119485: <http://trac.webkit.org/changeset/119485>
All reviewed patches have been landed. Closing bug.