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"
+
+// static
+void SigninMetrics::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 || count_added_to_cookie_jar ||
+        count_added_to_token) {
+      UMA_HISTOGRAM_COUNTS_100("Signin.ReconcilerAddedToCookieJar",
+                               count_added_to_cookie_jar);
+      UMA_HISTOGRAM_COUNTS_100("Signin.ReconcilerAddedToChrome",
+                               count_added_to_token);
+    }
+    if (!primary_accounts_same) {
+      base::RecordAction(
+          base::UserMetricsAction("AccountReconcilerDifferentPrimaryAccounts"));

[Roger Tawa OOO till Jul 10th, 2014/05/07 17:05:38]

Is there a reason to prefer a user action to a UMA_HISTOGRAM_BOOLEAN?

[Mike Lerman, 2014/05/07 18:49:37]

No, in fact the histogram will be able to filter against the Finch experiment.
I'll swap it for a histogram.

+    }

[Roger Tawa OOO till Jul 10th, 2014/05/07 17:05:38]

Indent whole function body two less.

[Mike Lerman, 2014/05/07 18:49:37]

Done.

+}
+