The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b2f4e66d3fe221e114ea43c7b1246d771a90859e

commit b2f4e66d3fe221e114ea43c7b1246d771a90859e
Author: Tanja Gornak <melandory@chromium.org>
Date: Fri Sep 07 15:07:31 2018

Record the metrics for the message arrived from the FCM channel.

Bug:  880204 , 801985

Change-Id: Iefce8533a32ba4d77961cee9d42845503b25c839
Reviewed-on: https://chromium-review.googlesource.com/1203833
Commit-Queue: Tatiana Gornak <melandory@chromium.org>
Reviewed-by: Pavel Yatsuk <pavely@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Jan Krcal <jkrcal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589517}
[modify] https://crrev.com/b2f4e66d3fe221e114ea43c7b1246d771a90859e/components/invalidation/impl/fcm_network_handler.cc
[modify] https://crrev.com/b2f4e66d3fe221e114ea43c7b1246d771a90859e/components/invalidation/impl/fcm_network_handler_unittests.cc
[modify] https://crrev.com/b2f4e66d3fe221e114ea43c7b1246d771a90859e/components/invalidation/impl/status.h
[modify] https://crrev.com/b2f4e66d3fe221e114ea43c7b1246d771a90859e/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/b2f4e66d3fe221e114ea43c7b1246d771a90859e/tools/metrics/histograms/histograms.xml