Fix base::Callback<>::IsCancelled handling on nested base::Callback

Previous implementation of IsCancelled doesn't have a specialization for
nested OnceCallback. That implies OnceCallback::IsCancelled returns false
when it's a nested callback and the inner callback is a cancelled OnceCallback.

Review-Url: https://codereview.chromium.org/2401623002
Cr-Commit-Position: refs/heads/master@{#423796}


CrOS-Libchrome-Original-Commit: 44adf07a8104da5e1ff35b9f57e30ad050d5f301
2 files changed
tree: d8b45ad49f9fd079be43e6dde8dfda81263ef1df
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/