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

ui/aura/window_port.h

Index: ui/aura/window_port.h
diff --git a/ui/aura/window_port.h b/ui/aura/window_port.h
new file mode 100644
index 0000000000000000000000000000000000000000..6f04399d391424f061297e26dfcd28cad0a6928b
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+++ b/ui/aura/window_port.h
@@ -0,0 +1,96 @@
+// 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>
+#include <string>
+
+#include "base/observer_list.h"
+#include "base/strings/string16.h"
+#include "ui/aura/aura_export.h"
+
+namespace gfx {
+class Rect;
+}
+
+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;
+
+  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;
+
+  // Called to move the child at |current_index| to |dest_index|. |dest_index|
+  // is calculated assuming the window at |current_index| has been removed, e.g.
+  //   Window* child = children_[current_index];
+  //   children_.erase(children_.begin() + current_index);
+  //   children_.insert(children_.begin() + dest_index, child);
+  virtual void OnWillMoveChild(size_t current_index, size_t dest_index) = 0;
+
+  virtual void OnVisibilityChanged(bool visible) = 0;
+
+  virtual void OnDidChangeBounds(const gfx::Rect& old_bounds,
+                                 const gfx::Rect& new_bounds) = 0;
+
+  // Called before a property is changed. The return value from this is supplied
+  // into OnPropertyChanged() so that WindowPort may pass data between the two
+  // calls.
+  virtual std::unique_ptr<WindowPortPropertyData> OnWillChangeProperty(
+      const void* key) = 0;
+
+  // Called after a property changes, but before observers are notified. |data|
+  // is the return value from OnWillChangeProperty().
+  virtual void OnPropertyChanged(
+      const void* key,
+      std::unique_ptr<WindowPortPropertyData> data) = 0;
+
+ protected:
+  // 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_