GitLab

Adds interfaces for persistent indicator integration. This includes:
- RegisterServerWithToken to register CameraHalServer with an added
  token-based authentication mechanism.
- RegisterClientWithToken to register CameraHalClient with token.
- TokenManager which issues and authenticates unguessable tokens for
  trusted HAL clients (Chrome, Android).
- Migrates Chrome VCD to register its CameraHalClient with tokens.
- CameraHalServerCallbacks for CameraHalServer to notify
  CameraHalDispatcher of updates on the server side, including camera
  activity changes.

Refer to go/cros-camera:dd:perm for the details on the design.

Bug: b:170075468
Test: Build and deploy simplechrome. Verify Chrome with new interface
    sends IPC calls cros-camera with both the old and new interface.

Change-Id: Idd52d184b922e2df5578fd38efcf01fa13334569
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2501104
Commit-Queue: Jasmine Chen <lnishan@google.com>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Wei Lee <wtlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827753}