Don't activate a window if screen is locked.

chrome/browser/chromeos/login/lock_window_aura.cc

Index: chrome/browser/chromeos/login/lock_window_aura.cc
diff --git a/chrome/browser/chromeos/login/lock_window_aura.cc b/chrome/browser/chromeos/login/lock_window_aura.cc
index 4fc118867778a40ae4adc72dee1d333d0709c477..2cbd850241412e75ea3644eb16912b6f9cba79f7 100644
--- a/chrome/browser/chromeos/login/lock_window_aura.cc
+++ b/chrome/browser/chromeos/login/lock_window_aura.cc
@@ -42,11 +42,9 @@ void LockWindowAura::Init() {
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.bounds = gfx::Rect(aura::RootWindow::GetInstance()->GetHostSize());
   views::Widget::Init(params);
-  // TODO(flackr): Use a property to specify this container rather than
-  // depending on shell implementation.
-  ash::Shell::GetInstance()->GetContainer(
-      ash::internal::kShellWindowId_LockScreenContainer)->
-      AddChild(GetNativeView());
+  GetNativeView()->set_stops_event_propagation(true);
+  // Let the shell pick the container.
+  GetNativeView()->SetParent(NULL);
 }
 
 }  // namespace chromeos