Focus kept on login screen.

ash/wm/event_client_impl.cc

Index: ash/wm/event_client_impl.cc
diff --git a/ash/wm/event_client_impl.cc b/ash/wm/event_client_impl.cc
index ab62f68dab9782ab85d2e6d77f365b36be051900..fcdc1b425d382c948e31b0135fff8e61d105c5ee 100644
--- a/ash/wm/event_client_impl.cc
+++ b/ash/wm/event_client_impl.cc
@@ -20,10 +20,10 @@ EventClientImpl::~EventClientImpl() {
 
 bool EventClientImpl::CanProcessEventsWithinSubtree(
     const aura::Window* window) const {
-  const aura::RootWindow* root_window =
-      window ? window->GetRootWindow() : NULL;
-  if (Shell::GetInstance()->session_state_delegate()->IsScreenLocked() &&
-      root_window) {
+  const aura::RootWindow* root_window = window ? window->GetRootWindow() : NULL;
+  if (!root_window)
+    return true;
+  if (Shell::GetInstance()->session_state_delegate()->IsUserSessionBlocked()) {
     const aura::Window* lock_screen_containers = Shell::GetContainer(
         root_window,
         kShellWindowId_LockScreenContainersContainer);