Implement oauth token external handler checking.

components/user_manager/user_manager.h

Index: components/user_manager/user_manager.h
diff --git a/components/user_manager/user_manager.h b/components/user_manager/user_manager.h
index 1ac1a7f5f7b4f20258b8441c2a54b13afcae9673..3f628dbbeb8cb363d2ad56adb398c1928d559634 100644
--- a/components/user_manager/user_manager.h
+++ b/components/user_manager/user_manager.h
@@ -8,9 +8,14 @@
 #include <string>
 
 #include "components/user_manager/user.h"
+#include "components/user_manager/user_id.h"
 #include "components/user_manager/user_manager_export.h"
 #include "components/user_manager/user_type.h"
 
+namespace base {
+class DictionaryValue;
+}
+
 namespace chromeos {
 class ScopedUserManagerEnabler;
 }
@@ -306,6 +311,21 @@ class USER_MANAGER_EXPORT UserManager {
   // Returns true if supervised users allowed.
   virtual bool AreSupervisedUsersAllowed() const = 0;
 
+  // Methods for storage/retrieval of per-user properties in Local State.
+
+  // Performs a lookup of properties associated with |user_id|. If found,
+  // returns |true| and fills |out_value|. |out_value| can be NULL, if
+  // only existence check is required.
+  virtual bool FindKnownUserPrefs(const UserID& user_id,
+                                  const base::DictionaryValue** out_value) = 0;
+
+  // Updates (or creates) properties associated with |user_id| based
+  // on |values|. |clear| defines if existing properties are cleared (|true|)
+  // or if it is just a incremental update (|false|).
+  virtual void UpdateKnownUserPrefs(const UserID& user_id,
+                                    const base::DictionaryValue& values,
+                                    bool clear) = 0;
+
  protected:
   // Sets UserManager instance.
   static void SetInstance(UserManager* user_manager);