Adds a porting layer so aura can be made to work with mus

ui/aura/window_tree_host_platform.h

 // Copyright 2015 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 UI_AURA_WINDOW_TREE_HOST_PLATFORM_H_
 #define UI_AURA_WINDOW_TREE_HOST_PLATFORM_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "ui/aura/aura_export.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/platform_window/platform_window.h"
 #include "ui/platform_window/platform_window_delegate.h"
 
 namespace aura {
 
+class WindowPort;
+
 // The unified WindowTreeHost implementation for platforms
 // that implement PlatformWindow.
 class AURA_EXPORT WindowTreeHostPlatform
     : public WindowTreeHost,
       public NON_EXPORTED_BASE(ui::PlatformWindowDelegate) {
  public:
   explicit WindowTreeHostPlatform(const gfx::Rect& bounds);
   ~WindowTreeHostPlatform() override;
 
   // WindowTreeHost:
   ui::EventSource* GetEventSource() override;
   gfx::AcceleratedWidget GetAcceleratedWidget() override;
   void ShowImpl() override;
   void HideImpl() override;
   gfx::Rect GetBounds() const override;
   void SetBounds(const gfx::Rect& bounds) override;
   gfx::Point GetLocationOnNativeScreen() const override;
   void SetCapture() override;
   void ReleaseCapture() override;
   void SetCursorNative(gfx::NativeCursor cursor) override;
   void MoveCursorToNative(const gfx::Point& location) override;
   void OnCursorVisibilityChangedNative(bool show) override;
 
  protected:
   WindowTreeHostPlatform();
+  explicit WindowTreeHostPlatform(std::unique_ptr<WindowPort> window_port);
+
   void SetPlatformWindow(std::unique_ptr<ui::PlatformWindow> window);
   ui::PlatformWindow* platform_window() { return window_.get(); }
 
   // ui::PlatformWindowDelegate:
   void OnBoundsChanged(const gfx::Rect& new_bounds) override;
   void OnDamageRect(const gfx::Rect& damaged_region) override;
   void DispatchEvent(ui::Event* event) override;
   void OnCloseRequest() override;
   void OnClosed() override;
   void OnWindowStateChanged(ui::PlatformWindowState new_state) override;
   void OnLostCapture() override;
   void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget,
                                     float device_pixel_ratio) override;
   void OnAcceleratedWidgetDestroyed() override;
   void OnActivationChanged(bool active) override;
 
  private:
   gfx::AcceleratedWidget widget_;
   std::unique_ptr<ui::PlatformWindow> window_;
   gfx::NativeCursor current_cursor_;
   gfx::Rect bounds_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostPlatform);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_TREE_HOST_PLATFORM_H_