chromeos: Don't explicitly set system tray visibility during initialization

ash/shelf/shelf_widget_unittest.cc

 // Copyright (c) 2013 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/shelf/shelf_widget.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/shelf_constants.h"
 #include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/shelf/shelf_layout_manager.h"
@@ skipping 173 matching lines @@
   WmShelf* shelf2 = WmShelf::ForWindow(roots[1]);
   ASSERT_TRUE(shelf1);
   ASSERT_TRUE(shelf2);
 
   // Both shelf controllers have a shelf widget.
   ShelfWidget* shelf_widget1 = shelf1->shelf_widget();
   ShelfWidget* shelf_widget2 = shelf2->shelf_widget();
   ASSERT_TRUE(shelf_widget1);
   ASSERT_TRUE(shelf_widget2);
 
+  // Simulate login.
   SetUserLoggedIn(true);
-  Shell::GetInstance()->CreateShelf();
+  SetSessionStarted(true);
 
   // The shelf view and status area horizontally fill the shelf widget.
   const int status_width1 =
       shelf_widget1->status_area_widget()->GetWindowBoundsInScreen().width();
   EXPECT_GT(status_width1, 0);
   EXPECT_EQ(shelf_widget1->GetContentsView()->width(),
             shelf1->GetShelfViewForTesting()->width() + status_width1);
 
   const int status_width2 =
       shelf_widget2->status_area_widget()->GetWindowBoundsInScreen().width();
@@ skipping 284 matching lines @@
 }
 
 TEST_P(ShelfWidgetTestWithDelegate, CreateLockedShelf) {
   // The auto hide state 'HIDDEN' is returned for any non-auto-hide behavior.
   TestCreateShelfWithInitialValues(SHELF_ALIGNMENT_BOTTOM_LOCKED,
                                    SHELF_AUTO_HIDE_BEHAVIOR_NEVER,
                                    SHELF_VISIBLE, SHELF_AUTO_HIDE_HIDDEN);
 }
 
 }  // namespace ash