aura: Unify WindowTreeHost for some platforms

ui/aura/window_tree_host_platform.h

Index: ui/aura/window_tree_host_platform.h
diff --git a/ui/aura/window_tree_host_win.h b/ui/aura/window_tree_host_platform.h
similarity index 73%
rename from ui/aura/window_tree_host_win.h
rename to ui/aura/window_tree_host_platform.h
index e49890d2f67ea7789136ba32711820ead8437e1d..79f41b1bf38f2431083aff3a04d0caf6a3fd965a 100644
--- a/ui/aura/window_tree_host_win.h
+++ b/ui/aura/window_tree_host_platform.h
@@ -1,26 +1,30 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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_WIN_H_
-#define UI_AURA_WINDOW_TREE_HOST_WIN_H_
+#ifndef UI_AURA_WINDOW_TREE_HOST_PLATFORM_H_
+#define UI_AURA_WINDOW_TREE_HOST_PLATFORM_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.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 AURA_EXPORT WindowTreeHostWin
+// The unified WindowTreeHost implementation for platforms
+// that implement PlatformWindow.
+class AURA_EXPORT WindowTreeHostPlatform
     : public WindowTreeHost,
       public NON_EXPORTED_BASE(ui::PlatformWindowDelegate) {
  public:
-  explicit WindowTreeHostWin(const gfx::Rect& bounds);
-  ~WindowTreeHostWin() override;
+  explicit WindowTreeHostPlatform(const gfx::Rect& bounds);
+  ~WindowTreeHostPlatform() override;
 
+ protected:
   // WindowTreeHost:
   ui::EventSource* GetEventSource() override;
   gfx::AcceleratedWidget GetAcceleratedWidget() override;
@@ -35,8 +39,7 @@ class AURA_EXPORT WindowTreeHostWin
   void MoveCursorToNative(const gfx::Point& location) override;
   void OnCursorVisibilityChangedNative(bool show) override;
 
- protected:
-  gfx::AcceleratedWidget hwnd() const { return widget_; }
+  ui::PlatformWindow* platform_window() { return platform_window_.get(); }
 
  private:
   // ui::PlatformWindowDelegate:
@@ -51,14 +54,15 @@ class AURA_EXPORT WindowTreeHostWin
                                     float device_pixel_ratio) override;
   void OnActivationChanged(bool active) override;
 
-  bool has_capture_;
-  gfx::Rect bounds_;
   gfx::AcceleratedWidget widget_;
   scoped_ptr<ui::PlatformWindow> window_;
+  bool has_capture_;
+  gfx::NativeCursor current_cursor_;
+  gfx::Rect bounds_;
 
-  DISALLOW_COPY_AND_ASSIGN(WindowTreeHostWin);
+  DISALLOW_COPY_AND_ASSIGN(WindowTreeHostPlatform);
 };
 
 }  // namespace aura
 
-#endif  // UI_AURA_WINDOW_TREE_HOST_WIN_H_
+#endif  // UI_AURA_WINDOW_TREE_HOST_PLATFORM_H_