UMA metrics - number of accounts per profile and account reconciler.

components/signin/core/browser/signin_metrics.cc

+// Copyright (c) 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 {
+
+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) {
+  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.AddedToCookieJarFirstRun",

[Alexei Svitkine (slow), 2014/05/09 14:16:16]

How about Signin.Reconciler.AddedToCookieJar.FirstRun and
Signin.Reconciler.AddedToCookieJar.SubsequentRun? and so on?

[Mike Lerman, 2014/05/09 20:13:27]

Done.

+                             count_added_to_cookie_jar);
+    UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToChromeFirstRun",
+                             count_added_to_token);
+    UMA_HISTOGRAM_BOOLEAN("Signin.Reconciler.DifferentPrimaryAccountsFirstRun",
+                          !primary_accounts_same);
+  } else {
+    UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToCookieJarSubsequentRun",
+                             count_added_to_cookie_jar);
+    UMA_HISTOGRAM_COUNTS_100("Signin.Reconciler.AddedToChromeSubsequentRun",
+                             count_added_to_token);
+    UMA_HISTOGRAM_BOOLEAN(
+        "Signin.Reconciler.DifferentPrimaryAccountsSubsequentRun",
+        !primary_accounts_same);
+  }
+}
+
+}  // namespace signin_metrics