mash: Break ash system tray dependencies on ash::ShelfWidget

ash/focus_cycler_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/common/focus_cycler.h"
 
 #include <memory>
 
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/wm_shell.h"
@@ skipping 78 matching lines @@
 
  protected:
   // Creates the system tray, returning true on success.
   bool CreateTray() {
     if (tray_)
       return false;
     WmWindow* parent =
         WmShell::Get()->GetRootWindowForNewWindows()->GetChildByShellWindowId(
             kShellWindowId_StatusContainer);
 
-    StatusAreaWidget* widget = new StatusAreaWidget(parent, shelf_widget());
+    StatusAreaWidget* widget = new StatusAreaWidget(parent, GetPrimaryShelf());
     widget->CreateTrayViews();
     widget->Show();
     tray_.reset(widget->system_tray());
     if (!tray_->GetWidget())
       return false;
     focus_cycler_->AddWidget(tray()->GetWidget());
     GetStatusAreaWidgetDelegate(tray_->GetWidget())->SetFocusCyclerForTesting(
         focus_cycler());
     return true;
   }
@@ skipping 313 matching lines @@
   // Cycle focus to the shelf.
   WmShell::Get()->focus_cycler()->RotateFocus(FocusCycler::FORWARD);
 
   // Cycle focus should go back to the browser.
   WmShell::Get()->focus_cycler()->RotateFocus(FocusCycler::FORWARD);
   EXPECT_TRUE(wm::IsActiveWindow(window.get()));
 }
 
 }  // namespace test
 }  // namespace ash