Generalize InterfacePtrSet for [Associated]InterfacePtr.

components/mus/ws/user_display_manager.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/ws/user_display_manager.h"
 
 #include "components/mus/ws/display.h"
 #include "components/mus/ws/display_manager.h"
 #include "components/mus/ws/window_manager_state.h"
 
@@ skipping 98 matching lines @@
       [&displays](mojom::DisplayManagerObserver* observer) {
         observer->OnDisplaysChanged(displays.Clone());
       });
   if (test_observer_)
     test_observer_->OnDisplaysChanged(displays.Clone());
 }
 
 void UserDisplayManager::AddObserver(
     mojom::DisplayManagerObserverPtr observer) {
   mojom::DisplayManagerObserver* observer_impl = observer.get();
-  display_manager_observers_.AddInterfacePtr(std::move(observer));
+  display_manager_observers_.AddPtr(std::move(observer));
   OnObserverAdded(observer_impl);
 }
 
 }  // namespace ws
 }  // namespace mus