Allow BLOCK_SHUTDOWN tasks during shutdown with SequencedWorkerPool redirected to TaskScheduler.

Before this CL, any task posted to a SequencedWorkerPool redirected to
TaskScheduler after
SequencedWorkerPool::Shutdown(int max_new_blocking_tasks_after_shutdown)
returned was ignored.

With this CL, |max_new_blocking_tasks_after_shutdown| BLOCK_SHUTDOWN
tasks are allowed to be posted after SequencedWorkerPool::Shutdown
returns.

BUG=622400

Review-Url: https://codereview.chromium.org/2389923004
Cr-Commit-Position: refs/heads/master@{#422775}


CrOS-Libchrome-Original-Commit: 387159105445bc8153931a02df261059b95b6a97
2 files changed
tree: e4f0ad59ca9e52b68b4564f392de53933170f659
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/