arc: Handle metrics for Auth operations.

chrome/browser/chromeos/arc/arc_optin_uma.cc

Index: chrome/browser/chromeos/arc/arc_optin_uma.cc
diff --git a/chrome/browser/chromeos/arc/arc_optin_uma.cc b/chrome/browser/chromeos/arc/arc_optin_uma.cc
index cea4e1c4a8762618f5ec4217a37c07fd0251ae4b..c8c435302781ffee9117ad62396a64dda5d2fc8f 100644
--- a/chrome/browser/chromeos/arc/arc_optin_uma.cc
+++ b/chrome/browser/chromeos/arc/arc_optin_uma.cc
@@ -10,6 +10,16 @@
 
 namespace arc {
 
+namespace {
+
+constexpr char kArcAuthHistogramPrefix[] = "Arc.Auth.";
+
+std::string GetAuthHistogramName(const std::string& key) {
+  return kArcAuthHistogramPrefix + key;

[dcheng, 2017/02/23 19:50:19]

Just add the Arc.Auth. prefix to the UMAs, it'll be easier to grep that way.

[khmel, 2017/02/23 20:06:35]

Done.

+}
+
+}  // namespace
+
 void UpdateOptInActionUMA(OptInActionType type) {
   UMA_HISTOGRAM_ENUMERATION("Arc.OptInAction", static_cast<int>(type),
                             static_cast<int>(OptInActionType::SIZE));
@@ -51,6 +61,20 @@ void UpdateProvisioningTiming(const base::TimeDelta& elapsed_time,
       ->AddTime(elapsed_time);
 }
 
+void UpdateAuthTiming(const std::string& key,

[dcheng, 2017/02/23 19:50:19]

And then pass this as const char* to save some temporary string constructions

[khmel, 2017/02/23 20:06:35]

Done.

+                      const base::TimeDelta& elapsed_time) {

[dcheng, 2017/02/23 19:50:19]

Nit: pass by value

[khmel, 2017/02/23 20:06:36]

Done.

+  base::Histogram::FactoryTimeGet(
+      GetAuthHistogramName(key), base::TimeDelta::FromSeconds(1) /* minimum */,
+      base::TimeDelta::FromMinutes(3) /* maximum */, 50 /* bucket_count */,
+      base::HistogramBase::kUmaTargetedHistogramFlag)
+      ->AddTime(elapsed_time);
+}
+
+void UpdateAuthAttempts(const std::string& key, int32_t value) {
+  UMA_HISTOGRAM_CUSTOM_COUNTS(GetAuthHistogramName(key), value, 0 /* minimum */,
+                              5 /* maximum */, 6 /* bucket_count */);
+}
+
 void UpdateSilentAuthCodeUMA(OptInSilentAuthCode state) {
   UMA_HISTOGRAM_ENUMERATION("Arc.OptInSilentAuthCode", static_cast<int>(state),
                             static_cast<int>(OptInSilentAuthCode::SIZE));