Replace the WAS_INSTALLED_BY_CUSTODIAN creation flag with a pref

extensions/browser/extension_prefs.h

Index: extensions/browser/extension_prefs.h
diff --git a/extensions/browser/extension_prefs.h b/extensions/browser/extension_prefs.h
index bae2126e755715670b87d5f5e1af6f103330df54..56c2aafebe0b1565597caa3bfd59909276e9cc50 100644
--- a/extensions/browser/extension_prefs.h
+++ b/extensions/browser/extension_prefs.h
@@ -409,6 +409,13 @@ class ExtensionPrefs : public ExtensionScopedPrefs, public KeyedService {
   void SetAllowFileAccess(const std::string& extension_id, bool allow);
   bool HasAllowFileAccessSetting(const std::string& extension_id) const;
 
+  // Returns true if this extension has been installed by the custodian of
+  // a supervised user.  It is relevant for supervised users and used to block

[Marc Treib, 2016/06/13 12:17:09]

nitty nit: only one space after "."

[mamir, 2016/06/13 14:15:57]

Done.

+  // them from uninstalling the extension for example.
+  bool WasInstalledByCustodian(const std::string& extension_id) const;
+  void SetWasInstalledByCustodian(const std::string& extension_id,
+                                  bool installed_by_custodian);
+
   // Saves ExtensionInfo for each installed extension with the path to the
   // version directory and the location. Blacklisted extensions won't be saved
   // and neither will external extensions the user has explicitly uninstalled.