Add WebNotificationTray

ash/system/status_area_widget.cc

Index: ash/system/status_area_widget.cc
diff --git a/ash/system/status_area_widget.cc b/ash/system/status_area_widget.cc
index e5f8ea62e6cb856564bad9983595130ab63a573d..d0053882f77c07990b4890a0bb937fd74246c090 100644
--- a/ash/system/status_area_widget.cc
+++ b/ash/system/status_area_widget.cc
@@ -31,15 +31,12 @@ StatusAreaWidget::~StatusAreaWidget() {
 }
 
 void StatusAreaWidget::AddTray(views::View* tray) {
-  widget_delegate_->AddChildView(tray);
-  widget_delegate_->Layout();
+  widget_delegate_->AddTray(tray);
 }
 
 void StatusAreaWidget::SetShelfAlignment(ShelfAlignment alignment) {
-  if (alignment == SHELF_ALIGNMENT_BOTTOM)
-    widget_delegate_->SetLayout(views::BoxLayout::kHorizontal);
-  else
-    widget_delegate_->SetLayout(views::BoxLayout::kVertical);
+  widget_delegate_->set_alignment(alignment);
+  widget_delegate_->UpdateLayout();
 }
 
 }  // namespace internal