Prepare status area to support multiple trays.

ash/system/tray/system_tray_unittest.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/system/tray/system_tray.h"
 
 #include <vector>
 
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "ash/test/ash_test_base.h"
 #include "base/utf_string_conversions.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
 namespace test {
 
 namespace {
 
 SystemTray* CreateSystemTray() {
-  SystemTray* tray = new SystemTray;
   internal::StatusAreaWidget* widget = new internal::StatusAreaWidget;
-  widget->AddTray(tray);
-  tray->CreateItems();
+  widget->CreateTrayViews(NULL);
   widget->Show();
-  return tray;
+  return widget->system_tray();
 }
 
 // Trivial item implementation that tracks its views for testing.
 class TestItem : public SystemTrayItem {
  public:
   TestItem() : tray_view_(NULL) {}
 
   virtual views::View* CreateTrayView(user::LoginStatus status) {
     tray_view_ = new views::View;
     // Add a label so it has non-zero width.
@@ skipping 189 matching lines @@
   tray->ShowDefaultView(BUBBLE_USE_EXISTING);
   RunAllPendingInMessageLoop();
 
   EXPECT_EQ(bubble_bounds.ToString(), test_item->default_view()->GetWidget()->
       GetWindowScreenBounds().ToString());
   EXPECT_EQ(widget, test_item->default_view()->GetWidget());
 }
 
 }  // namespace test
 }  // namespace ash