Implement newly designed sign-in related histograms for desktop platorms.

components/signin/core/browser/signin_metrics.cc

Index: components/signin/core/browser/signin_metrics.cc
diff --git a/components/signin/core/browser/signin_metrics.cc b/components/signin/core/browser/signin_metrics.cc
index a154d1105b81bd9751a26219a581780ad109a0bd..a215d282d98474ff002822bd952234eaff572f8f 100644
--- a/components/signin/core/browser/signin_metrics.cc
+++ b/components/signin/core/browser/signin_metrics.cc
@@ -21,6 +21,20 @@ DifferentPrimaryAccounts ComparePrimaryAccounts(bool primary_accounts_same,
   return COOKIE_AND_TOKEN_PRIMARIES_DIFFERENT;
 }
 
+void LogSigninAccessPoint(AccessPoint access_point, bool is_completed) {
+  if (!is_completed) {
+    UMA_HISTOGRAM_ENUMERATION("Signin.SigninStartedAccessPoint", access_point,
+                              ACCESS_POINT_MAX);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Signin.SigninCompletedAccessPoint", access_point,
+                              ACCESS_POINT_MAX);
+  }
+}
+
+void LogSigninReason(Reason reason) {
+  UMA_HISTOGRAM_ENUMERATION("Signin.SigninReason", reason, REASON_MAX);
+}
+
 void LogSigninAccountReconciliation(int total_number_accounts,
                                     int count_added_to_cookie_jar,
                                     int count_removed_from_cookie_jar,
@@ -73,10 +87,6 @@ void LogSigninProfile(bool is_first_run, base::Time install_date) {
                        elapsed_time.InMinutes());
 }
 
-void LogSigninSource(Source source) {
-  UMA_HISTOGRAM_ENUMERATION("Signin.SigninSource", source, HISTOGRAM_MAX);
-}
-
 void LogSigninAddAccount() {
   // Account signin may fail for a wide variety of reasons. There is no
   // explicit false, but one can compare this value with the various UI