We want a toggle-able flag in web inspector's console for showing a timestamp per line. This PR only includes the backend support for sending a timestamp with the console message.
Pull request: https://github.com/WebKit/WebKit/pull/6743
<rdar://problem/102773623>
Committed 258675@main (d69d0f7bc8d8): <https://commits.webkit.org/258675@main> Reviewed commits have been landed. Closing PR #6743 and removing active labels.