Cros login screen: fix scroll issue with login-dev-overlay

Bug: 1112301
Change-Id: I24e68ca470e639c6ad704d0fd268c6a8c98b8731
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2613052Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Commit-Queue: Yunke Zhou <yunkez@google.com>
Cr-Commit-Position: refs/heads/master@{#841035}

ash/login/ui/lock_debug_view.cc

@@ -826,6 +826,9 @@ void LockDebugView::Layout() {
   lock_->SetBoundsRect(GetLocalBounds());
   container_->SetPosition(gfx::Point());
   container_->SizeToPreferredSize();
+
+  for (views::View* child : container_->children())
+    child->Layout();
 }
 
 void LockDebugView::AddOrRemoveUsersButtonPressed(int delta) {