Signin screen and locked screen status area focus advancing

ash/common/system/status_area_widget_delegate.cc

Index: ash/common/system/status_area_widget_delegate.cc
diff --git a/ash/common/system/status_area_widget_delegate.cc b/ash/common/system/status_area_widget_delegate.cc
index 6663b4cc5ec0d1f162099f196779fb014e2e9163..cdf93c1bdcab36b5bbd4090cb6d331078d776e5e 100644
--- a/ash/common/system/status_area_widget_delegate.cc
+++ b/ash/common/system/status_area_widget_delegate.cc
@@ -69,7 +69,25 @@ void StatusAreaWidgetDelegate::SetFocusCyclerForTesting(
 }
 
 views::View* StatusAreaWidgetDelegate::GetDefaultFocusableChild() {
-  return child_at(0);
+  return default_last_focusable_child_ ? GetLastFocusableChild()
+                                       : GetFirstFocusableChild();
+}
+
+views::FocusSearch* StatusAreaWidgetDelegate::GetFocusSearch() {
+  return custom_focus_traversable_ ? custom_focus_traversable_->GetFocusSearch()
+                                   : AccessiblePaneView::GetFocusSearch();
+}
+
+views::FocusTraversable* StatusAreaWidgetDelegate::GetFocusTraversableParent() {
+  return custom_focus_traversable_
+             ? custom_focus_traversable_->GetFocusTraversableParent()
+             : AccessiblePaneView::GetFocusTraversableParent();
+}
+
+views::View* StatusAreaWidgetDelegate::GetFocusTraversableParentView() {
+  return custom_focus_traversable_
+             ? custom_focus_traversable_->GetFocusTraversableParentView()
+             : AccessiblePaneView::GetFocusTraversableParentView();
 }
 
 views::Widget* StatusAreaWidgetDelegate::GetWidget() {