Add Installer.OSAgeDays metric
This adds a new metric conveying the age of the running OS instance,
where this is defined as the time-span between the current wall-clock
time and the time-stamp of the /etc/lsb-release file. This metric is
reported daily.
BUG=chromium:304950
TEST=New unit tests for daily metrics + unit tests pass. Manual test
for Installer.OSAgeDays by inspecting chrome://histograms.
Change-Id: I6713bed6730641a95443372a3e3166c4e1dc64ee
Reviewed-on: https://chromium-review.googlesource.com/172162
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: David Zeuthen <zeuthen@chromium.org>
Tested-by: David Zeuthen <zeuthen@chromium.org>
diff --git a/constants.h b/constants.h
index 1e69df8..5fbfa06 100644
--- a/constants.h
+++ b/constants.h
@@ -34,6 +34,7 @@
extern const char kPrefsCurrentResponseSignature[];
extern const char kPrefsCurrentUrlFailureCount[];
extern const char kPrefsCurrentUrlIndex[];
+extern const char kPrefsDailyMetricsLastReportedAt[];
extern const char kPrefsDeltaUpdateFailures[];
extern const char kPrefsFullPayloadAttemptNumber[];
extern const char kPrefsLastActivePingDay[];