ui: Cleanup class/struct forward declarations

ui/aura/mus/window_tree_client.h

 // Copyright 2014 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.
 
 #ifndef UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 #define UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 35 matching lines @@
 class CaptureSynchronizer;
 class DragDropControllerMus;
 class FocusSynchronizer;
 class InFlightBoundsChange;
 class InFlightChange;
 class InFlightFocusChange;
 class InFlightPropertyChange;
 class InFlightVisibleChange;
 class WindowMus;
 class WindowPortMus;
-struct WindowPortInitData;
 struct WindowPortPropertyData;
 class WindowTreeClientDelegate;
 class WindowTreeClientPrivate;
 class WindowTreeClientObserver;
 class WindowTreeHost;
 class WindowTreeHostMus;
 
-namespace client {
-class FocusClient;
-}
-
 using EventResultCallback = base::Callback<void(ui::mojom::EventResult)>;
 
 // Manages the connection with mus.
 //
 // WindowTreeClient is owned by the creator. Generally when the delegate gets
 // one of OnEmbedRootDestroyed() or OnLostConnection() it should delete the
 // WindowTreeClient.
 //
 // When WindowTreeClient is deleted all windows are deleted (and observers
 // notified).
@@ skipping 419 matching lines @@
   std::unique_ptr<DragDropControllerMus> drag_drop_controller_;
 
   base::WeakPtrFactory<WindowTreeClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeClient);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_TREE_CLIENT_H_