Converted IncognitoForced boolean policy into IncognitoModeAvailability enum policy.

chrome/browser/prefs/pref_value_map.h

Index: chrome/browser/prefs/pref_value_map.h
diff --git a/chrome/browser/prefs/pref_value_map.h b/chrome/browser/prefs/pref_value_map.h
index 100aa3404626bc44c30db0bc7f405fa0a529482b..f8995ce386fe9af6003cafb44942dc234154a488 100644
--- a/chrome/browser/prefs/pref_value_map.h
+++ b/chrome/browser/prefs/pref_value_map.h
@@ -58,6 +58,13 @@ class PrefValueMap {
   // Sets the value for |key| to the string |value|.
   void SetString(const std::string& key, const std::string& value);
 
+  // Gets an int value for |key| and stores it in |value|. Returns true if
+  // the value was found and of the proper type.
+  bool GetInteger(const std::string& key, int* value) const;
+
+  // Sets the value for |key| to the int |value|.
+  void SetInteger(const std::string& key, const int value);
+
   // Compares this value map against |other| and stores all key names that have
   // different values in |differing_keys|. This includes keys that are present
   // only in one of the maps.