Don't activate a window if screen is locked.

ash/shell_unittest.cc

Index: ash/shell_unittest.cc
diff --git a/ash/shell_unittest.cc b/ash/shell_unittest.cc
index 6604799d6cf5b3dd2ea95208189aaef480d17253..17c185a20baf5aec836ab1c1fe0adc257caf1ad2 100644
--- a/ash/shell_unittest.cc
+++ b/ash/shell_unittest.cc
@@ -242,9 +242,8 @@ TEST_F(ShellTest, IsScreenLocked) {
 
   // A lock screen window locks the screen.
   views::Widget* lock_widget = CreateTestWindow(widget_params);
-  ash::Shell::GetInstance()->GetContainer(
-      ash::internal::kShellWindowId_LockScreenContainer)->
-      AddChild(lock_widget->GetNativeView());
+  lock_widget->GetNativeView()->set_stops_event_propagation(true);
+  lock_widget->GetNativeView()->SetParent(NULL);
   lock_widget->Show();
   EXPECT_TRUE(Shell::GetInstance()->IsScreenLocked());
   lock_widget->Hide();