views/mus: Chaneg how Widget activation works in mus.

ui/wm/core/focus_controller.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_WM_CORE_FOCUS_CONTROLLER_H_
 #define UI_WM_CORE_FOCUS_CONTROLLER_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 31 matching lines @@
 //   itself as an observer of the active and focused windows).
 class WM_EXPORT FocusController : public aura::client::ActivationClient,
                                   public aura::client::FocusClient,
                                   public ui::EventHandler,
                                   public aura::WindowObserver {
  public:
   // |rules| cannot be NULL.
   explicit FocusController(FocusRules* rules);
   ~FocusController() override;
 
- private:
+ protected:
   // Overridden from aura::client::ActivationClient:
   void AddObserver(aura::client::ActivationChangeObserver* observer) override;
   void RemoveObserver(
       aura::client::ActivationChangeObserver* observer) override;
   void ActivateWindow(aura::Window* window) override;
   void DeactivateWindow(aura::Window* window) override;
   aura::Window* GetActiveWindow() override;
   aura::Window* GetActivatableWindow(aura::Window* window) override;
   aura::Window* GetToplevelWindow(aura::Window* window) override;
   bool CanActivateWindow(aura::Window* window) const override;
@@ skipping 11 matching lines @@
   void OnScrollEvent(ui::ScrollEvent* event) override;
   void OnTouchEvent(ui::TouchEvent* event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
 
   // Overridden from aura::WindowObserver:
   void OnWindowVisibilityChanged(aura::Window* window, bool visible) override;
   void OnWindowDestroying(aura::Window* window) override;
   void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
   void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
 
+ private:
   // Internal implementation that coordinates window focus and activation
   // changes.
   void FocusAndActivateWindow(
       aura::client::ActivationChangeObserver::ActivationReason reason,
       aura::Window* window);
 
   // Internal implementation that sets the focused window, fires events etc.
   // This function must be called with a valid focusable window.
   void SetFocusedWindow(aura::Window* window);
 
@@ skipping 36 matching lines @@
   base::ObserverList<aura::client::FocusChangeObserver> focus_observers_;
 
   ScopedObserver<aura::Window, aura::WindowObserver> observer_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(FocusController);
 };
 
 }  // namespace wm
 
 #endif  // UI_WM_CORE_FOCUS_CONTROLLER_H_