Signin screen and locked screen status area focus advancing

ash/common/system/status_area_widget_delegate.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 ASH_COMMON_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_
 #define ASH_COMMON_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "ash/common/shelf/shelf_types.h"
 #include "base/macros.h"
@@ skipping 15 matching lines @@
   void AddTray(views::View* tray);
 
   // Called whenever layout might change (e.g. alignment changed).
   void UpdateLayout();
 
   // Sets the focus cycler.
   void SetFocusCyclerForTesting(const FocusCycler* focus_cycler);
 
   void set_alignment(ShelfAlignment alignment) { alignment_ = alignment; }
 
+  void set_custom_focus_traversable(
+      views::FocusTraversable* custom_focus_traversable) {
+    custom_focus_traversable_ = custom_focus_traversable;
+  }
+
+  void set_default_last_focusable_child(bool default_last_focusable_child) {
+    default_last_focusable_child_ = default_last_focusable_child;
+  }
+
   // Overridden from views::AccessiblePaneView.
   View* GetDefaultFocusableChild() override;
+  views::FocusSearch* GetFocusSearch() override;
+  views::FocusTraversable* GetFocusTraversableParent() override;
+  views::View* GetFocusTraversableParentView() override;
 
   // Overridden from views::View:
   views::Widget* GetWidget() override;
   const views::Widget* GetWidget() const override;
 
   // Overridden from ui::EventHandler:
   void OnGestureEvent(ui::GestureEvent* event) override;
 
   // views::WidgetDelegate overrides:
   bool CanActivate() const override;
   void DeleteDelegate() override;
 
  protected:
   // Overridden from views::View:
   void ChildPreferredSizeChanged(views::View* child) override;
   void ChildVisibilityChanged(views::View* child) override;
 
  private:
   void UpdateWidgetSize();
 
   // Sets a border on |child|. If |extend_border_to_edge| is true, then an extra
   // wide border is added to extend the view's hit region to the edge of the
   // screen.
   void SetBorderOnChild(views::View* child, bool extend_border_to_edge);
 
+  views::FocusTraversable* custom_focus_traversable_ = nullptr;
+
+  // When true, the default focus of the status area widget is the last
+  // focusable child.
+  bool default_last_focusable_child_ = false;
+
   const FocusCycler* focus_cycler_for_testing_;
 
   // TODO(jamescook): Get this from WmShelf.
   ShelfAlignment alignment_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusAreaWidgetDelegate);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_