Add GrabWindowSnapshotAsync tests

chrome/test/base/view_event_test_base.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 "chrome/test/base/view_event_test_base.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 123 matching lines @@
   shell_delegate->test_session_state_delegate()
       ->SetActiveUserSessionStarted(true);
   context = ash::Shell::GetPrimaryRootWindow();
 #endif  // !OS_WIN
   aura::Env::CreateInstance();
 #elif defined(USE_AURA)
   // Instead of using the ash shell, use an AuraTestHelper to create and manage
   // the test screen.
   aura_test_helper_.reset(
       new aura::test::AuraTestHelper(base::MessageLoopForUI::current()));
-  aura_test_helper_->SetUp();
+  bool allow_test_contexts = true;
+  aura_test_helper_->SetUp(allow_test_contexts);
   context = aura_test_helper_->root_window();
 #endif  // !USE_ASH && USE_AURA
 
   window_ = views::Widget::CreateWindowWithContext(this, context);
 }
 
 void ViewEventTestBase::TearDown() {
   if (window_) {
 #if defined(OS_WIN) && !defined(USE_AURA)
     DestroyWindow(window_->GetNativeWindow());
@@ skipping 92 matching lines @@
   dnd_thread_.reset(NULL);
 }
 
 void ViewEventTestBase::RunTestMethod(const base::Closure& task) {
   StopBackgroundThread();
 
   task.Run();
   if (HasFatalFailure())
     Done();
 }