commit 548902a5c197b94b9cc55e72d518292fd434c4fa
author Yuta Kitamura <yutak@chromium.org> Fri Oct 26 07:05:16 2018
committer Commit Bot <commit-bot@chromium.org> Fri Oct 26 07:05:16 2018
tree 6bda507b7289ae3ccf8555a488b871ea5b307cbb
parent cc60c182ad2260ea070d9b399de9bbdd451f6b78

Spin off TaskObserver into a dedicated header.

This CL moves the definition of MessageLoopCurrent::TaskObserver to
an individual header task/task_observer.h.

The motivation of this change comes from crrev.com/c/1295617.
MessageLoop is going away soon(-ish?), and Blink doesn't want to depend
on base::MessageLoop. It makes more sense to have TaskObserver in a
stand-alone header, given this current situation.

This CL does not touch any use sites of TaskObserver. The alias
MessageLoop::TaskObserver is still available, pending future mass
replacements.

Bug: 826203
Change-Id: I9e17bae3586e29cb76b23f5e247307760dac9a1f
Reviewed-on: https://chromium-review.googlesource.com/c/1298944
Commit-Queue: Yuta Kitamura <yutak@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603015}