Converted IncognitoForced boolean policy into IncognitoModeAvailability enum policy.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 29e9d9a030cee32db0983d0515294242167422ff..8880458aaacf60dddc9cc8c128c9c6415a4ca62d 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -163,8 +163,11 @@ const char kSafeBrowsingReportingEnabled[] =
 // Boolean that is true when Incognito support is enabled.
 const char kIncognitoEnabled[] = "incognito.enabled";
 
-// Boolean that specifies if all user sessions should be forced into Incognito.
-const char kIncognitoForced[] = "incognito.forced";
+// Enum that specifies whether Incognito mode is:
+// 0 - Enabled. Default behaviour. Default mode is available on demand.
+// 1 - Disabled. Used cannot browse pages in Incognito mode.
+// 2 - Forced. All pages/sessions are forced into Incognito.
+const char kIncognitoModeAvailability[] = "incognito.mode_availability";
 
 // Boolean that is true when Suggest support is enabled.
 const char kSearchSuggestEnabled[] = "search.suggest_enabled";