Converts WindowTreeClientTest to be in terms of aura

ui/aura/test/aura_test_base.h

 // Copyright (c) 2012 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_TEST_AURA_TEST_BASE_H_
 #define UI_AURA_TEST_AURA_TEST_BASE_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 72 matching lines @@
 
   TestWindowTree* window_tree() { return helper_->window_tree(); }
   WindowTreeClient* window_tree_client_impl() {
     return helper_->window_tree_client();
   }
   ui::mojom::WindowTreeClient* window_tree_client();
 
   // WindowTreeClientDelegate:
   void OnEmbed(std::unique_ptr<WindowTreeHostMus> window_tree_host) override;
   void OnUnembed(Window* root) override;
-  void OnEmbedRootDestroyed(Window* root) override;
+  void OnEmbedRootDestroyed(WindowTreeHostMus* window_tree_host) override;
   void OnLostConnection(WindowTreeClient* client) override;
   void OnPointerEventObserved(const ui::PointerEvent& event,
                               Window* target) override;
 
   // WindowManagerDelegate:
   void SetWindowManagerClient(WindowManagerClient* client) override;
   bool OnWmSetBounds(Window* window, gfx::Rect* bounds) override;
   bool OnWmSetProperty(
       Window* window,
       const std::string& name,
@@ skipping 51 matching lines @@
  private:
   bool setup_called_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(AuraTestBaseWithType);
 };
 
 }  // namespace test
 }  // namespace aura
 
 #endif  // UI_AURA_TEST_AURA_TEST_BASE_H_