Move more from WmShell to Shell

ash/mus/bridge/wm_shell_mus.cc

Index: ash/mus/bridge/wm_shell_mus.cc
diff --git a/ash/mus/bridge/wm_shell_mus.cc b/ash/mus/bridge/wm_shell_mus.cc
index 0e804cc615404abda05cfe9535b16110a5c91d6b..35d1ac39eeb9d6ce2f451cad32ec5a6a16784888 100644
--- a/ash/mus/bridge/wm_shell_mus.cc
+++ b/ash/mus/bridge/wm_shell_mus.cc
@@ -90,8 +90,6 @@ WmShellMus::WmShellMus(
   DCHECK(primary_root_window_);
 
   immersive_handler_factory_.reset(new ImmersiveHandlerFactoryMus);
-
-  SetKeyboardUI(KeyboardUIMus::Create(window_manager_->connector()));
 }
 
 WmShellMus::~WmShellMus() {
@@ -287,6 +285,10 @@ WmShellMus::CreateImmersiveFullscreenController() {
   return base::MakeUnique<ImmersiveFullscreenController>();
 }
 
+std::unique_ptr<KeyboardUI> WmShellMus::CreateKeyboardUI() {
+  return KeyboardUIMus::Create(window_manager_->connector());
+}
+
 std::unique_ptr<KeyEventWatcher> WmShellMus::CreateKeyEventWatcher() {
   // TODO: needs implementation for mus, http://crbug.com/649600.
   NOTIMPLEMENTED();