dbus: Add IsInterfaceRegistered to ObjectManager

This change adds a new public method to check whether a specific
interface is currently registered with ObjectManager. It will be used
mainly for testing.

BUG=b:193712484
TEST=autoninja -c out/Default chrome

Change-Id: I46b0ad58afd7334693393b1c9a0291bb94a58dd0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3089691
Commit-Queue: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#912402}
NOKEYCHECK=True
GitOrigin-RevId: 94ccec0eace4bfddd4153c3fb1abeb58ad6659c9
2 files changed