Handle the new Google cert in ThirdPartyMetricsRecorder.

Also:
- reference the new signer in doc comments.
- change "Microsoft Inc." (which isn't a thing) to "Microsoft
  Corporation" in doc comments.

BUG=928220
R=pmonette@chromium.org
TBR=wfh@chromium.org

Change-Id: Ib611652a3945eb0f1bf8f9075eccc53f6a367ff6
Reviewed-on: https://chromium-review.googlesource.com/c/1458056
Commit-Queue: Greg Thompson <grt@chromium.org>
Auto-Submit: Greg Thompson <grt@chromium.org>
Reviewed-by: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633066}
3 files changed