Removes code using mus client lib

ui/views/test/native_widget_factory_mus.cc

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "ui/views/test/native_widget_factory.h"
-
-#include "ui/views/mus/window_manager_connection.h"
-#include "ui/views/test/test_platform_native_widget.h"
-#include "ui/views/widget/native_widget_aura.h"
-
-namespace views {
-namespace test {
-
-NativeWidget* CreatePlatformNativeWidgetImpl(
-    const Widget::InitParams& init_params,
-    Widget* widget,
-    uint32_t type,
-    bool* destroyed) {
-  return new TestPlatformNativeWidget<NativeWidgetAura>(
-      widget, type == kStubCapture, destroyed);
-}
-
-NativeWidget* CreatePlatformDesktopNativeWidgetImpl(
-    const Widget::InitParams& init_params,
-    Widget* widget,
-    bool* destroyed) {
-  return WindowManagerConnection::Get()->CreateNativeWidgetMus(
-      std::map<std::string, std::vector<uint8_t>>(), init_params, widget);
-}
-
-}  // namespace test
-}  // namespace views