Add UMA stat to track home button and page prefs

chrome/browser/prefs/pref_metrics_service.cc

Index: chrome/browser/prefs/pref_metrics_service.cc
diff --git a/chrome/browser/prefs/pref_metrics_service.cc b/chrome/browser/prefs/pref_metrics_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8314dd773169c92918dc3f68e2dbc4a32bb74507
--- /dev/null
+++ b/chrome/browser/prefs/pref_metrics_service.cc
@@ -0,0 +1,67 @@
+// Copyright (c) 2013 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 "chrome/browser/prefs/pref_metrics_service.h"
+
+#include "base/metrics/histogram.h"
+#include "base/prefs/pref_service.h"
+#include "chrome/browser/profiles/incognito_helpers.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/pref_names.h"
+#include "components/browser_context_keyed_service/browser_context_dependency_manager.h"
+
+PrefMetricsService::PrefMetricsService(Profile* profile)
+    : profile_(profile) {
+  RecordLaunchPrefs();
+}
+
+PrefMetricsService::~PrefMetricsService() {
+}
+
+void PrefMetricsService::RecordLaunchPrefs() {
+  UMA_HISTOGRAM_BOOLEAN("Settings.ShowHomeButton",
+      profile_->GetPrefs()->GetBoolean(prefs::kShowHomeButton));
+  UMA_HISTOGRAM_BOOLEAN("Settings.HomePageIsNewTabPage",
+      profile_->GetPrefs()->GetBoolean(prefs::kHomePageIsNewTabPage));
+}
+
+// static
+PrefMetricsService::Factory* PrefMetricsService::Factory::GetInstance() {
+  return Singleton<PrefMetricsService::Factory>::get();
+}
+
+// static
+PrefMetricsService* PrefMetricsService::Factory::GetForProfile(
+    Profile* profile) {
+  return static_cast<PrefMetricsService*>(
+      GetInstance()->GetServiceForBrowserContext(profile, true));
+}
+
+PrefMetricsService::Factory::Factory()
+    : BrowserContextKeyedServiceFactory(
+        "PrefMetricsService",
+        BrowserContextDependencyManager::GetInstance()) {
+}
+
+PrefMetricsService::Factory::~Factory() {
+}
+
+BrowserContextKeyedService*
+PrefMetricsService::Factory::BuildServiceInstanceFor(
+    content::BrowserContext* profile) const {
+  return new PrefMetricsService(static_cast<Profile*>(profile));
+}
+
+bool PrefMetricsService::Factory::ServiceIsCreatedWithBrowserContext() const {
+  return true;
+}
+
+bool PrefMetricsService::Factory::ServiceIsNULLWhileTesting() const {
+  return false;
+}
+
+content::BrowserContext* PrefMetricsService::Factory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  return chrome::GetBrowserContextRedirectedInIncognito(context);
+}