mash/wm: Fix detecting container windows.

mash/wm/window_manager.h

 // Copyright 2015 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 MASH_WM_WINDOW_MANAGER_H_
 #define MASH_WM_WINDOW_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "components/mus/common/types.h"
 #include "components/mus/public/cpp/window_manager_delegate.h"
 #include "components/mus/public/cpp/window_observer.h"
+#include "components/mus/public/cpp/window_tracker.h"
 #include "components/mus/public/interfaces/window_manager.mojom.h"
 #include "mash/session/public/interfaces/session.mojom.h"
+#include "mash/wm/disconnected_app_handler.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace mash {
 namespace wm {
 
 class RootWindowController;
 
-class WindowManager : public mus::WindowObserver,
+class WindowManager : public mus::WindowTracker,
                       public mus::WindowManagerDelegate,
                       public session::mojom::ScreenlockStateListener {
  public:
   WindowManager();
   ~WindowManager() override;
 
   void Initialize(RootWindowController* root_controller,
                   session::mojom::Session* session);
 
   mus::WindowManagerClient* window_manager_client() {
     return window_manager_client_;
   }
 
  private:
   gfx::Rect CalculateDefaultBounds(mus::Window* window) const;
   gfx::Rect GetMaximizedWindowBounds() const;
 
   mus::Window* NewTopLevelWindow(
       std::map<std::string, std::vector<uint8_t>>* properties);
 
   // mus::WindowObserver:
   void OnTreeChanging(const TreeChangeParams& params) override;
-  void OnWindowEmbeddedAppDisconnected(mus::Window* window) override;
 
   // WindowManagerDelegate:
   void SetWindowManagerClient(mus::WindowManagerClient* client) override;
   bool OnWmSetBounds(mus::Window* window, gfx::Rect* bounds) override;
   bool OnWmSetProperty(
       mus::Window* window,
       const std::string& name,
       std::unique_ptr<std::vector<uint8_t>>* new_data) override;
   mus::Window* OnWmCreateTopLevelWindow(
       std::map<std::string, std::vector<uint8_t>>* properties) override;
   void OnAccelerator(uint32_t id, const ui::Event& event) override;
 
   // session::mojom::ScreenlockStateListener:
   void ScreenlockStateChanged(bool locked) override;
 
   RootWindowController* root_controller_;
   mus::WindowManagerClient* window_manager_client_;
+  DisconnectedAppHandler disconnected_app_handler_;
 
   mojo::Binding<session::mojom::ScreenlockStateListener> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManager);
 };
 
 }  // namespace wm
 }  // namespace mash
 
 #endif  // MASH_WM_WINDOW_MANAGER_H_