Makes it possible for clients to directly create WindowTreeHostMus

ui/aura/window_port.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 UI_AURA_WINDOW_PORT_H_
 #define UI_AURA_WINDOW_PORT_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 10 matching lines @@
 namespace aura {
 
 class Window;
 class WindowObserver;
 
 // See comments in OnWillChangeProperty() for details.
 struct AURA_EXPORT WindowPortPropertyData {
   virtual ~WindowPortPropertyData() {}
 };
 
-// See comments in Init() for details.
-struct AURA_EXPORT WindowPortInitData {
-  virtual ~WindowPortInitData() {}
-};
-
 // WindowPort defines an interface to enable Window to be used with or without
 // mus. WindowPort is owned by Window and called at key points in Windows
 // lifetime that enable Window to be used in both environments.
 //
 // If a Window is created without an explicit WindowPort then
 // Env::CreateWindowPort() is used to create the WindowPort.
 class AURA_EXPORT WindowPort {
  public:
   virtual ~WindowPort() {}
 
-  // Called from Window::Init(). The return value of this is supplied to
-  // OnInitDone() and is used to allow the WindowPort to pass data between the
-  // two functions.
-  virtual std::unique_ptr<WindowPortInitData> OnPreInit(Window* window) = 0;
-
-  virtual void OnPostInit(std::unique_ptr<WindowPortInitData> data) = 0;
+  // Called from Window::Init().
+  virtual void OnPreInit(Window* window) = 0;
 
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) = 0;
 
   // Called when a window is being added as a child. |child| may already have
   // a parent, but its parent is not the Window this WindowPort is associated
   // with.
   virtual void OnWillAddChild(Window* child) = 0;
 
   virtual void OnWillRemoveChild(Window* child) = 0;
 
@@ skipping 25 matching lines @@
   // Returns the WindowPort associated with a Window.
   static WindowPort* Get(Window* window);
 
   // Returns the ObserverList of a Window.
   static base::ObserverList<WindowObserver, true>* GetObservers(Window* window);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_PORT_H_