GitLab

Expose NumberOfInputStreamsWithPermission related APIs up to
CrasAudioHandler.

- Add CrasAudioHandler::ClientType enum class.
- Add OnNumberOfInputStreamsWithPermissionChanged to
  CrasAudioHandler::Observer.
- Add GetNumberOfInputStreamsWithPermission to CrasAudioHandler.

BUG=b:174336267
TEST=chromeos_unittests
TEST=Build and use input streams to trigger dbus from CRAS

Change-Id: Ia040a310e8e4604076ecc89018700d1d210f29d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2579931Reviewed-by: Jason Lin <lxj@google.com>
Reviewed-by: Hsinyu Chao <hychao@chromium.org>
Commit-Queue: Chih-Yang Hsia <paulhsia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836959}