Add NigoriConfigurationWithInvalidatedCredentials histogram

To confirm that metrics descrepancies in SyncUSSNigori experiment
caused by sync paused state, this CL adds
NigoriConfigurationWithInvalidatedCredentials histogram.

Original attempt (http://crrev/c/1971924) of adding similar histograms
was buggy because histograms were recorded on configuration failure,
while it couldn't be even started without access token. They will be
cleaned up in follow-up CL.

New histogram recorded when access token invalidated, it always happen
if sync is in paused state. There is some noise, but it's not expected
to be large or not-relevant for original aims:
1. Any non-transient auth errors which could invalidate access token
could be interested as well, because they would lead to the same
metrics descrepancies while everything works as intended.
2. Non-transient auth errors should happen together with Nigori-only
configuration, which happens only due to first-time sync or enabling
USS Nigori first time, so the noise level shouldn't be high.

Bug: 1041871
Change-Id: If35e01f8d17286753753a5d5405d5ccec6882e3e
Auto-Submit: Maksim Moskvitin <>
Commit-Queue: Steven Holte <>
Reviewed-by: Steven Holte <>
Reviewed-by: Mikel Astiz <>
Cr-Commit-Position: refs/heads/master@{#731771}
8 files changed