Make RunLoop 100% standalone.

MessageLoop is no longer a friend of RunLoop :)!

The only minor dependency remaining shows up in tests as allowing
nestable tasks in a scope (different from allowing nested loops on a
thread in general) is still a MessageLoop concept. I plan to move that
to RunLoop as well in a follow-up.

R=danakj@chromium.org

Bug: 703346
Change-Id: I0a6269c94de179d97c14855499edd70be9e1d1af
Reviewed-on: https://chromium-review.googlesource.com/594352
Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491258}

CrOS-Libchrome-Original-Commit: e2b632b52572c12f4a2c130e557ac2a0f1ca2358
4 files changed
tree: 0196051198c2877e6a76aafcc53d502be80366dc
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/