Differentiate primary account compares on GAIA cookie presence.

components/signin/core/browser/signin_metrics.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/signin/core/browser/signin_metrics.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/user_metrics.h"
 
 namespace signin_metrics {
 
+// Enum for the ways in which primary account detection is done.
+enum DifferentPrimaryAccounts {
+  // token and cookie had same primary accounts.
+  ACCOUNTS_SAME = 0,
+  // Deprecated. Indicates different primary accounts.
+  UNUSED_ACCOUNTS_DIFFERENT,
+  // No GAIA cookie present, so the primaries are considered different.
+  NO_COOKIE_PRESENT,
+  // There was at least one cookie and one token, and the primaries differed.
+  COOKIE_AND_TOKEN_PRIMARIES_DIFFERENT,
+  NUM_DIFFERENT_PRIMARY_ACCOUNT_METRICS,
+};
+
+// Helper method to determine which |DifferentPrimaryAccounts| applies.
+DifferentPrimaryAccounts ComparePrimaryAccounts(bool primary_accounts_same,
+    int pre_count_gaia_cookies) {

[Alexei Svitkine (slow), 2014/06/17 19:43:04]

Nit: Align or if it doesn't fit, wrap both params.

+  if (primary_accounts_same)
+    return ACCOUNTS_SAME;
+  if (pre_count_gaia_cookies == 0)
+    return NO_COOKIE_PRESENT;
+  return COOKIE_AND_TOKEN_PRIMARIES_DIFFERENT;
+}
+
 void LogSigninAccountReconciliation(int total_number_accounts,
                                     int count_added_to_cookie_jar,
                                     int count_added_to_token,
                                     bool primary_accounts_same,
-                                    bool is_first_reconcile) {
+                                    bool is_first_reconcile,
+                                    int pre_count_gaia_cookies) {
   UMA_HISTOGRAM_COUNTS_100("Profile.NumberOfAccountsPerProfile",
                            total_number_accounts);
   // We want to include zeroes in the counts of added accounts to easily
   // capture _relatively_ how often we merge accounts.
   if (is_first_reconcile) {
     UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToCookieJar.FirstRun",
                              count_added_to_cookie_jar);
     UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToChrome.FirstRun",
                              count_added_to_token);
-    UMA_HISTOGRAM_BOOLEAN("Signin.Reconciler.DifferentPrimaryAccounts.FirstRun",
-                          !primary_accounts_same);
+    UMA_HISTOGRAM_ENUMERATION(
+        "Signin.Reconciler.DifferentPrimaryAccounts.FirstRun",
+        ComparePrimaryAccounts(primary_accounts_same, pre_count_gaia_cookies),
+        NUM_DIFFERENT_PRIMARY_ACCOUNT_METRICS);
   } else {
     UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToCookieJar.SubsequentRun",
                              count_added_to_cookie_jar);
     UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToChrome.SubsequentRun",
                              count_added_to_token);
-    UMA_HISTOGRAM_BOOLEAN(
+    UMA_HISTOGRAM_ENUMERATION(
         "Signin.Reconciler.DifferentPrimaryAccounts.SubsequentRun",
-        !primary_accounts_same);
+        ComparePrimaryAccounts(primary_accounts_same, pre_count_gaia_cookies),
+        NUM_DIFFERENT_PRIMARY_ACCOUNT_METRICS);
   }
 }
 
 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
   // flows that lead to account sign-in, and deduce that the difference
   // counts the failures.
   UMA_HISTOGRAM_BOOLEAN("Signin.AddAccount", true);
 }
 
 }  // namespace signin_metrics