Add synchronous and asynchronous methods to ManagedUserSyncService to get the list of managed users.

chrome/browser/managed_mode/managed_user_sync_service.h

Index: chrome/browser/managed_mode/managed_user_sync_service.h
diff --git a/chrome/browser/managed_mode/managed_user_sync_service.h b/chrome/browser/managed_mode/managed_user_sync_service.h
index b0aa4b8ae3d201bab7ee8de3b655ce87863a3f70..4c7642350af1c672d692ae02fa516eb75bef5973 100644
--- a/chrome/browser/managed_mode/managed_user_sync_service.h
+++ b/chrome/browser/managed_mode/managed_user_sync_service.h
@@ -5,6 +5,9 @@
 #ifndef CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_SYNC_SERVICE_H_
 #define CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_SYNC_SERVICE_H_
 
+#include <vector>
+
+#include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/prefs/pref_change_registrar.h"
@@ -13,15 +16,23 @@
 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
 #include "sync/api/syncable_service.h"
 
-class PrefService;
+namespace base {
+class DictionaryValue;
+}
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
+class PrefService;
+
 class ManagedUserSyncService : public BrowserContextKeyedService,
                                public syncer::SyncableService {
  public:
+  // For use with GetAllManagedUsers() below.
+  typedef base::Callback<void(const base::DictionaryValue*)>
+      ManagedUsersCallback;
+
   virtual ~ManagedUserSyncService();
 
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
@@ -34,6 +45,17 @@ class ManagedUserSyncService : public BrowserContextKeyedService,
                       const std::string& master_key);
   void DeleteManagedUser(const std::string& id);
 
+  // Returns a dictionary containing all managed users managed by this
+  // custodian. This method should only be called once this service has started
+  // syncing managed users (i.e. has finished its initial merge of local and
+  // server-side data, via MergeDataAndStartSyncing), as the stored data might
+  // be outdated before that.
+  const base::DictionaryValue* GetManagedUsers();
+
+  // Calls the passed |callback| with a dictionary containing all managed users
+  // managed by this custodian.
+  void GetManagedUsersAsync(const ManagedUsersCallback& callback);
+
   // BrowserContextKeyedService implementation:
   virtual void Shutdown() OVERRIDE;
 
@@ -62,6 +84,8 @@ class ManagedUserSyncService : public BrowserContextKeyedService,
   void NotifyManagedUserAcknowledged(const std::string& managed_user_id);
   void NotifyManagedUsersSyncingStopped();
 
+  void DispatchCallbacks();
+
   PrefService* prefs_;
   PrefChangeRegistrar pref_change_registrar_;
 
@@ -70,6 +94,8 @@ class ManagedUserSyncService : public BrowserContextKeyedService,
 
   ObserverList<ManagedUserSyncServiceObserver> observers_;
 
+  std::vector<ManagedUsersCallback> callbacks_;
+
   DISALLOW_COPY_AND_ASSIGN(ManagedUserSyncService);
 };