GitLab

Update the TRIGGER_EVENT description in ukm.xml to accurately reflect
the values recorded. This update was missed in previous patchset that
added metrics for the toolbar button triggering UI.

BUG=859563

Change-Id: Ia270c452195a46120802d6de00032583007f7459
Reviewed-on: https://chromium-review.googlesource.com/c/1333998Reviewed-by: Filip Gorski <fgorski@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608999}