Prevent mouse from getting stuck on second display in login

ash/test/ash_test_helper.cc

 // Copyright 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/test/ash_test_helper.h"
 
 #include "ash/ash_switches.h"
 #include "ash/shell.h"
 #include "ash/test/display_manager_test_api.h"
 #include "ash/test/shell_test_api.h"
@@ skipping 21 matching lines @@
       test_shell_delegate_(NULL) {
   CHECK(message_loop_);
 #if defined(USE_X11)
   aura::test::SetUseOverrideRedirectWindowByDefault(true);
 #endif
 }
 
 AshTestHelper::~AshTestHelper() {
 }
 
-void AshTestHelper::SetUp() {
+void AshTestHelper::SetUp(bool start_session) {
   // Disable animations during tests.
   zero_duration_mode_.reset(new ui::ScopedAnimationDurationScaleMode(
       ui::ScopedAnimationDurationScaleMode::ZERO_DURATION));
   ui::InitializeInputMethodForTesting();
 
   // Creates Shell and hook with Desktop.
   test_shell_delegate_ = new TestShellDelegate;
 
   // Creates MessageCenter since g_browser_process is not created in AshTestBase
   // tests.
   message_center::MessageCenter::Initialize();
 
 #if defined(OS_CHROMEOS)
   // Create CrasAudioHandler for testing since g_browser_process is not
   // created in AshTestBase tests.
   chromeos::CrasAudioHandler::InitializeForTesting();
 #endif
 
   ash::Shell::CreateInstance(test_shell_delegate_);
   Shell* shell = Shell::GetInstance();
-  test_shell_delegate_->test_session_state_delegate()->
-      SetActiveUserSessionStarted(true);
-  test_shell_delegate_->test_session_state_delegate()->SetHasActiveUser(true);
+  if (start_session) {
+    test_shell_delegate_->test_session_state_delegate()->
+        SetActiveUserSessionStarted(true);
+    test_shell_delegate_->test_session_state_delegate()->
+        SetHasActiveUser(true);
+  }
 
   test::DisplayManagerTestApi(shell->display_manager()).
       DisableChangeDisplayUponHostResize();
   ShellTestApi(shell).DisableOutputConfiguratorAnimation();
 }
 
 void AshTestHelper::TearDown() {
   // Tear down the shell.
   Shell::DeleteInstance();
 
@@ skipping 21 matching lines @@
 aura::RootWindow* AshTestHelper::CurrentContext() {
   aura::RootWindow* root_window = Shell::GetActiveRootWindow();
   if (!root_window)
     root_window = Shell::GetPrimaryRootWindow();
   DCHECK(root_window);
   return root_window;
 }
 
 }  // namespace test
 }  // namespace ash