Converts chrome to aura-mus

ui/aura/mus/focus_synchronizer.h

 // 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.
 
 #ifndef UI_AURA_MUS_FOCUS_SYNCHRONIZER_H_
 #define UI_AURA_MUS_FOCUS_SYNCHRONIZER_H_
 
 #include "base/macros.h"
 #include "ui/aura/client/focus_change_observer.h"
 #include "ui/aura/env_observer.h"
 
 namespace ui {
 namespace mojom {
 class WindowTree;
 }
 }
 
 namespace aura {
 
+class Env;
 class FocusSynchronizerDelegate;
 class WindowMus;
 
 namespace client {
 class FocusClient;
 }
 
 // FocusSynchronizer is resonsible for keeping focus in sync between aura
 // and the mus server.
 class FocusSynchronizer : public client::FocusChangeObserver,
@@ skipping 15 matching lines @@
   void SetActiveFocusClient(client::FocusClient* focus_client);
 
   // Called internally to set |focused_window_| and update the server.
   void SetFocusedWindow(WindowMus* window);
 
   // Overriden from client::FocusChangeObserver:
   void OnWindowFocused(Window* gained_focus, Window* lost_focus) override;
 
   // Overrided from EnvObserver:
   void OnWindowInitialized(Window* window) override;
+  void OnWillDestroyEnv() override;
   void OnActiveFocusClientChanged(client::FocusClient* focus_client,
                                   Window* window) override;
 
   FocusSynchronizerDelegate* delegate_;
   ui::mojom::WindowTree* window_tree_;
 
   client::FocusClient* active_focus_client_ = nullptr;
 
   bool setting_focus_ = false;
   WindowMus* window_setting_focus_to_ = nullptr;
   WindowMus* focused_window_ = nullptr;
 
+  // Cached so we can detect if Env is destroyed before us.

[sadrul, 2016/12/16 02:17:48]

When does this happen?

[sky, 2016/12/16 03:51:50]

It appears content destroys Env before the WindowTreeclient is destroyed. That
is likely error prone. I'll file a bug on it.

+  Env* env_;
+
   DISALLOW_COPY_AND_ASSIGN(FocusSynchronizer);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_FOCUS_SYNCHRONIZER_H_