Signin screen and locked screen status area focus advancing

ash/common/system/status_area_widget.h

Index: ash/common/system/status_area_widget.h
diff --git a/ash/common/system/status_area_widget.h b/ash/common/system/status_area_widget.h
index c432ebeb6738949edffe8fcc334e0de409713745..f0b402d7216be81a8f1027a863d5b93533146ac8 100644
--- a/ash/common/system/status_area_widget.h
+++ b/ash/common/system/status_area_widget.h
@@ -89,6 +89,7 @@ class ASH_EXPORT StatusAreaWidget : public views::Widget,
   // Overridden from views::Widget:
   const ui::NativeTheme* GetNativeTheme() const override;
   void OnNativeWidgetActivationChanged(bool active) override;
+  void OnKeyEvent(ui::KeyEvent* event) override;
 
   // ShelfBackgroundAnimatorObserver:
   void UpdateShelfItemBackground(int alpha) override;
@@ -108,6 +109,8 @@ class ASH_EXPORT StatusAreaWidget : public views::Widget,
 #endif
   void AddOverviewButtonTray();
 
+  void HandleFocusKeyEvent(ui::KeyEvent* event);
+
   // Weak pointers to View classes that are parented to StatusAreaWidget:
   StatusAreaWidgetDelegate* status_area_widget_delegate_;
   OverviewButtonTray* overview_button_tray_;