[Smart Lock] Add UMA metrics to measure duration of unlock.

chrome/browser/signin/easy_unlock_metrics.cc

Index: chrome/browser/signin/easy_unlock_metrics.cc
diff --git a/chrome/browser/signin/easy_unlock_metrics.cc b/chrome/browser/signin/easy_unlock_metrics.cc
index ba46c7f6479ade8cbd853d36add7859e7c02036e..722bd505c264ddf00a8f69a52e3f9f991dc41f70 100644
--- a/chrome/browser/signin/easy_unlock_metrics.cc
+++ b/chrome/browser/signin/easy_unlock_metrics.cc
@@ -7,12 +7,20 @@
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 
+void RecordEasyUnlockSigninDuration(const base::TimeDelta& duration) {
+  UMA_HISTOGRAM_MEDIUM_TIMES("EasyUnlock.AuthEvent.SignIn.Duration", duration);
+}
+
 void RecordEasyUnlockSigninEvent(EasyUnlockAuthEvent event) {
   DCHECK_LT(event, EASY_UNLOCK_AUTH_EVENT_COUNT);
   UMA_HISTOGRAM_ENUMERATION("EasyUnlock.AuthEvent.SignIn", event,
                             EASY_UNLOCK_AUTH_EVENT_COUNT);
 }
 
+void RecordEasyUnlockScreenUnlockDuration(const base::TimeDelta& duration) {
+  UMA_HISTOGRAM_MEDIUM_TIMES("EasyUnlock.AuthEvent.Unlock.Duration", duration);
+}
+
 void RecordEasyUnlockScreenUnlockEvent(EasyUnlockAuthEvent event) {
   DCHECK_LT(event, EASY_UNLOCK_AUTH_EVENT_COUNT);
   UMA_HISTOGRAM_ENUMERATION("EasyUnlock.AuthEvent.Unlock", event,