GitLab

Convert the remaining bits that still use the old mojo types for
mirroring::mojom::SessionObserver to the new mojo types, and adapt
unit tests.

Bug: 955171
Change-Id: I715380ce54a13b93b7da99202f42b3a02a3519e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1807827
Commit-Queue: Mario Sanchez Prada <mario@igalia.com>
Reviewed-by: Yuri Wiitala <miu@chromium.org>
Reviewed-by: Brandon Tolsch <btolsch@chromium.org>
Reviewed-by: Oksana Zhuravlova <oksamyt@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697977}