As per https://github.com/whatwg/console/issues/27#issuecomment-289312546
and https://bugs.chromium.org/p/chromium/issues/detail?id=706804 we're
leaving the console timeline/timelineEnd methods out of the specification
and testing that implementations do not expose them (relevant WPTs at
https://github.com/web-platform-tests/wpt/blob/master/console/console-tests-historical.any.js).
Their implementations should be removed from Chrome, one of the last
implementers of these legacy methods. The same goes for markTimeline, as
it is deprecated in Chrome and not being included in the spec.

R=bmeurer@chromium.org, kozyatinskiy@chromium.org

Bug: chromium:706804
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ibe05848fb664d26d16eeb5bdf6f519c1eeb4b2df
Reviewed-on: https://chromium-review.googlesource.com/1082112Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Commit-Queue: Dominic Farolino <domfarolino@gmail.com>
Cr-Commit-Position: refs/heads/master@{#53973}