The description will be used to annotate roots in the heap snapshot.

Bug: chromium:811842
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ic5c9a89d1921cabddb06783f08ba63740e72820d
Reviewed-on: https://chromium-review.googlesource.com/916564Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51286}