Converted IncognitoForced boolean policy into IncognitoModeAvailability enum policy.

chrome/browser/prefs/incognito_mode_prefs.h

+// 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.
+
+#ifndef CHROME_BROWSER_PREFS_INCOGNITO_MODE_PREFS_H_
+#define CHROME_BROWSER_PREFS_INCOGNITO_MODE_PREFS_H_
+#pragma once
+
+#include "base/basictypes.h"
+
+class PrefService;
+
+// Specifies Incognito mode availability preferences.
+class IncognitoModePrefs {
+ public:
+  // Possible values for Incognito mode availability. Please, do not change
+  // the order of entries since numeric values are exposed to users.
+  enum Availability {
+    // Incognito mode enabled. Users may open pages in both Incognito mode and
+    // normal mode (the default behaviour).
+    ENABLED = 0,
+    // Incognito mode disabled. Users may not open pages in Incognito mode.
+    // Only normal mode is available for browsing.
+    DISABLED,
+    // Incognito mode forced. Users may open pages *ONLY* in Incognito mode.
+    // Normal mode is not available for browsing.
+    FORCED,
+
+    AVAILABILITY_NUM_TYPES
+  };
+
+  // Register incognito related preferences.
+  static void RegisterUserPrefs(PrefService* prefs);
+
+  // Returns kIncognitoModeAvailability preference value stored
+  // in the given pref service.
+  static Availability GetAvailability(const PrefService* prefs);
+
+  // Sets kIncognitoModeAvailability preference to the specified availability
+  // value.
+  static void SetAvailability(PrefService* prefs,
+                              const Availability availability);
+
+  // Converts in_value into the corresponding Availability value. Returns true
+  // if conversion is successful (in_value is valid). Otherwise, returns false
+  // and *out_value is set to ENABLED.
+  static bool IntToAvailability(int in_value, Availability* out_value);
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(IncognitoModePrefs);
+};
+
+#endif  // CHROME_BROWSER_PREFS_INCOGNITO_MODE_PREFS_H_