Introduce dbus::Error.

And hide DBusError from outside of dbus/.

BUG=1459945
TEST=Tryjob

Change-Id: Iea55971dd4d714a4139675a56e73b86755dd6eaf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4664079
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1166347}
NOKEYCHECK=True
GitOrigin-RevId: 3afb59a10d2d130f17195d2d611195ee439c917e
15 files changed