Make LogoutButtonTray a regular View

ash/system/status_area_widget_delegate.h

Index: ash/system/status_area_widget_delegate.h
diff --git a/ash/system/status_area_widget_delegate.h b/ash/system/status_area_widget_delegate.h
index c60df6a248aaf3844b55e108d624f841fc9583d2..38a248b153eef2661164f9bc8697de87c181815a 100644
--- a/ash/system/status_area_widget_delegate.h
+++ b/ash/system/status_area_widget_delegate.h
@@ -14,12 +14,13 @@
 
 namespace ash {
 class FocusCycler;
+class WmShelf;
 
 // The View for the status area widget.
 class ASH_EXPORT StatusAreaWidgetDelegate : public views::AccessiblePaneView,
                                             public views::WidgetDelegate {
  public:
-  StatusAreaWidgetDelegate();
+  explicit StatusAreaWidgetDelegate(WmShelf* wm_shelf);
   ~StatusAreaWidgetDelegate() override;
 
   // Add a tray view to the widget (e.g. system tray, web notifications).
@@ -31,8 +32,6 @@ class ASH_EXPORT StatusAreaWidgetDelegate : public views::AccessiblePaneView,
   // Sets the focus cycler.
   void SetFocusCyclerForTesting(const FocusCycler* focus_cycler);
 
-  void set_alignment(ShelfAlignment alignment) { alignment_ = alignment; }
-
   // Overridden from views::AccessiblePaneView.
   View* GetDefaultFocusableChild() override;
 
@@ -60,11 +59,9 @@ class ASH_EXPORT StatusAreaWidgetDelegate : public views::AccessiblePaneView,
   // screen.
   void SetBorderOnChild(views::View* child, bool extend_border_to_edge);
 
+  WmShelf* const wm_shelf_;
   const FocusCycler* focus_cycler_for_testing_;
 
-  // TODO(jamescook): Get this from WmShelf.
-  ShelfAlignment alignment_;
-
   DISALLOW_COPY_AND_ASSIGN(StatusAreaWidgetDelegate);
 };