Change FocusSynchronizer to maintain active focus client and window.

ui/views/mus/desktop_window_tree_host_mus.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_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_MUS_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_MUS_H_
 
 #include <memory>
 #include <set>
 
 #include "base/macros.h"
-#include "ui/aura/env_observer.h"
+#include "ui/aura/mus/focus_synchronizer_observer.h"
 #include "ui/aura/mus/window_tree_host_mus.h"
 #include "ui/aura/window_observer.h"
 #include "ui/views/mus/mus_client_observer.h"
 #include "ui/views/mus/mus_export.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_observer.h"
 
 namespace wm {
 class CursorManager;
 }
 
 namespace views {
 
 class VIEWS_MUS_EXPORT DesktopWindowTreeHostMus
     : public DesktopWindowTreeHost,
       public MusClientObserver,
       public WidgetObserver,
+      public aura::FocusSynchronizerObserver,
       public aura::WindowObserver,
-      public aura::WindowTreeHostMus,
-      public aura::EnvObserver {
+      public aura::WindowTreeHostMus {
  public:
   DesktopWindowTreeHostMus(
       internal::NativeWidgetDelegate* native_widget_delegate,
       DesktopNativeWidgetAura* desktop_native_widget_aura,
       const std::map<std::string, std::vector<uint8_t>>* mus_properties);
   ~DesktopWindowTreeHostMus() override;
 
   // Called when the window was deleted on the server.
   void ServerDestroyedWindow() { CloseNow(); }
 
@@ skipping 81 matching lines @@
   bool ShouldUpdateWindowTransparency() const override;
   bool ShouldUseDesktopNativeCursorManager() const override;
   bool ShouldCreateVisibilityController() const override;
 
   // MusClientObserver:
   void OnWindowManagerFrameValuesChanged() override;
 
   // WidgetObserver:
   void OnWidgetActivationChanged(Widget* widget, bool active) override;
 
+  // aura::FocusSynchronizerObserver:
+  void OnActiveFocusClientChanged(aura::client::FocusClient* focus_client,
+                                  aura::Window* window) override;
+
   // aura::WindowObserver:
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
                                intptr_t old) override;
 
   // aura::WindowTreeHostMus:
   void ShowImpl() override;
   void HideImpl() override;
   void SetBoundsInPixels(const gfx::Rect& bounds_in_pixels) override;
 
-  // aura::EnvObserver:
-  void OnWindowInitialized(aura::Window* window) override;
-  void OnActiveFocusClientChanged(aura::client::FocusClient* focus_client,
-                                  aura::Window* window) override;
-
   internal::NativeWidgetDelegate* native_widget_delegate_;
 
   DesktopNativeWidgetAura* desktop_native_widget_aura_;
 
   // We can optionally have a parent which can order us to close, or own
   // children who we're responsible for closing when we CloseNow().
   DesktopWindowTreeHostMus* parent_ = nullptr;
   std::set<DesktopWindowTreeHostMus*> children_;
 
   bool is_active_ = false;
 
   std::unique_ptr<wm::CursorManager> cursor_manager_;
 
   bool auto_update_client_area_ = true;
 
   // Used so that Close() isn't immediate.
   base::WeakPtrFactory<DesktopWindowTreeHostMus> close_widget_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopWindowTreeHostMus);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_MUS_H_