Converted IncognitoForced boolean policy into IncognitoModeAvailability enum policy.

chrome/browser/prefs/incognito_mode_prefs.cc

+// Copyright (c) 2011 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/incognito_mode_prefs.h"
+
+#include "base/logging.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/common/pref_names.h"
+
+// static
+bool IncognitoModePrefs::IntToAvailability(
+    int in_value, Availability* out_value) {
+  if (in_value < 0 || in_value >= AVAILABILITY_NUM_TYPES) {
+    *out_value = ENABLED;
+    return false;
+  }
+  *out_value = static_cast<Availability>(in_value);
+  return true;
+}
+
+// static
+IncognitoModePrefs::Availability IncognitoModePrefs::GetAvailability(
+    const PrefService* pref_service) {
+  DCHECK(pref_service);
+  int pref_value = pref_service->GetInteger(prefs::kIncognitoModeAvailability);
+  Availability result = IncognitoModePrefs::ENABLED;
+  bool valid = IntToAvailability(pref_value, &result);
+  DCHECK(valid);
+  return result;
+}
+
+// static
+void IncognitoModePrefs::RegisterUserPrefs(PrefService* pref_service) {
+  DCHECK(pref_service);
+  pref_service->RegisterIntegerPref(prefs::kIncognitoModeAvailability,
+                                    IncognitoModePrefs::ENABLED,
+                                    PrefService::UNSYNCABLE_PREF);
+}