FrameGenerator should not be created until an AcceleratedWidget is available

services/ui/ws/platform_display_default.h

 // 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.
 
 #ifndef SERVICES_UI_WS_PLATFORM_DISPLAY_DEFAULT_H_
 #define SERVICES_UI_WS_PLATFORM_DISPLAY_DEFAULT_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 65 matching lines @@
 #if !defined(OS_ANDROID)
   std::unique_ptr<ui::ImageCursors> image_cursors_;
 #endif
 
   PlatformDisplayDelegate* delegate_ = nullptr;
   std::unique_ptr<FrameGenerator> frame_generator_;
 
   display::ViewportMetrics metrics_;
   std::unique_ptr<ui::PlatformWindow> platform_window_;
   gfx::AcceleratedWidget widget_;
+  ServerWindow* root_window_;
+  float init_device_scale_factor_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformDisplayDefault);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_PLATFORM_DISPLAY_DEFAULT_H_