Signin screen and locked screen status area focus advancing

ash/common/system/status_area_widget_delegate.cc

 // 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.
 
 #include "ash/common/system/status_area_widget_delegate.h"
 
 #include "ash/ash_export.h"
 #include "ash/common/focus_cycler.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/shelf_constants.h"
@@ skipping 51 matching lines @@
 }
 
 StatusAreaWidgetDelegate::~StatusAreaWidgetDelegate() {}
 
 void StatusAreaWidgetDelegate::SetFocusCyclerForTesting(
     const FocusCycler* focus_cycler) {
   focus_cycler_for_testing_ = focus_cycler;
 }
 
 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() {
   return View::GetWidget();
 }
 
 const views::Widget* StatusAreaWidgetDelegate::GetWidget() const {
   return View::GetWidget();
 }
 
@@ skipping 147 matching lines @@
   }
   child->SetBorder(views::Border::CreateEmptyBorder(top_edge, left_edge,
                                                     bottom_edge, right_edge));
   // Layout on |child| needs to be updated based on new border value before
   // displaying; otherwise |child| will be showing with old border size.
   // Fix for crbug.com/623438.
   child->Layout();
 }
 
 }  // namespace ash