Fills athena background always.

athena/virtual_keyboard/virtual_keyboard_manager_impl.cc

Index: athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
diff --git a/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc b/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
index 7acca11f4980eeaebda15d14b182de3b9641b25d..abb0b3f84fd85d7d719f4631af07015211a04639 100644
--- a/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
+++ b/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
@@ -88,6 +88,7 @@ class VirtualKeyboardManagerImpl : public VirtualKeyboardManager {
     // ResetInstance takes ownership.
     keyboard::KeyboardController::ResetInstance(controller);
     aura::Window* kb_container = controller->GetContainerWindow();
+    FillLayoutManager::SetAlwaysFill(kb_container);
     container_->AddChild(kb_container);
     kb_container->Show();
   }