Introduce OnceClosure and BindOnce

This CL adds another flag, RepeatMode, to base::Callback to make a Callback
variant that can be run only once, and exposes it as OnceCallback.
This also adds a base:::Bind variant to create an OneOnce, and
adds provides conversions and constraints between Callbacks.

BUG=554299

Review-Url: https://codereview.chromium.org/2042223002
Cr-Commit-Position: refs/heads/master@{#418177}


CrOS-Libchrome-Original-Commit: 27d1e313968955f1a120b65b31e316263365b1b3
8 files changed
tree: 389e9db1ef90aeb348bd080b2438ee80e12c6888
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/