[omnibox] Update third_party/metrics_proto to match internal protos

This just runs the blaze command to roll metrics_proto to match the
latest internal version.

Bug: 963680
Change-Id: I4a36fc15b03476241928052fb59d0b907fc0b000
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1620006
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661440}
4 files changed