Migrate MessageLoop::ScopedNestableTaskAllower usage to MessageLoopCurrent

And use the new argument-less constructor to avoid being redundant.

R=altimin@chromium.org
TBR=thestig@chromium.org

Bug: 781352, 825327
Change-Id: I57a0bd50934f402ec24409fa4b315bafec83bd7f
Reviewed-on: https://chromium-review.googlesource.com/1020288
Commit-Queue: Gabriel Charette <gab@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552221}

CrOS-Libchrome-Original-Commit: d258c5155b1bb1ca893ee6f86345c341bb6d98f4
2 files changed
tree: 9e94f8f9d24d857d8ca8e7b3f7908c1a294fb0da
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/