Differentiate primary account compares on GAIA cookie presence.

components/signin/core/browser/signin_metrics.h

Index: components/signin/core/browser/signin_metrics.h
diff --git a/components/signin/core/browser/signin_metrics.h b/components/signin/core/browser/signin_metrics.h
index 0dfa97a06ddb9c2ff6c83e2fa2b18d268269bfb0..9eb78ad4a2f8bf22b36d64c61d1eaaa25db056be 100644
--- a/components/signin/core/browser/signin_metrics.h
+++ b/components/signin/core/browser/signin_metrics.h
@@ -7,6 +7,19 @@
 
 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,
+};
+
 // Log to UMA histograms and UserCounts stats about a single execution of the
 // AccountReconciler.
 // |total_number_accounts| - How many accounts are in the browser for this
@@ -19,11 +32,14 @@ namespace signin_metrics {
 //                           and the token service were different; else true.
 // |is_first_reconcile| - True if these stats are from the first execution of
 //                        the AccountReconcilor.
+// |pre_count_gaia_cookies| - How many GAIA cookies were present before
+//                            the AccountReconcilor began modifying the state.
 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);
 
 // Track a successful signin.
 void LogSigninAddAccount();