Introduce SingleThreadTaskRunnerThreadMode

This allows callers creating SingleThreadTaskRunners to specify if the
backing thread for the SingleThreadTaskRunner can be shared with other
task runners or reserved for the exclusive use of the
SingleThreadTaskRunner.

BUG=720058

Review-Url: https://codereview.chromium.org/2873733003
Cr-Commit-Position: refs/heads/master@{#471287}


CrOS-Libchrome-Original-Commit: 94520d71c9197a0f9b0bf4b426e4d676725828d1
6 files changed
tree: 14d1afb6964cf66a9227d131c28ca5f99a9d5288
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/