win32: Add a PlatformWindow implementation for Windows.

ui/platform_window/platform_window.h

 // Copyright 2014 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_PLATFORM_WINDOW_PLATFORM_WINDOW_H_
 #define UI_PLATFORM_WINDOW_PLATFORM_WINDOW_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "ui/platform_window/platform_window_export.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace ui {
 
 class PlatformWindowDelegate;
 
 // Platform window.
 //
 // Each instance of PlatformWindow represents a single window in the
 // underlying platform windowing system (i.e. X11/Win/OSX).
-class PLATFORM_WINDOW_EXPORT PlatformWindow {
+class PlatformWindow {
  public:
   virtual ~PlatformWindow() {}
 
   virtual void Show() = 0;
   virtual void Hide() = 0;
   virtual void Close() = 0;
 
   // Sets and gets the bounds of the platform-window. Note that the bounds is in
   // physical pixel coordinates.
   virtual void SetBounds(const gfx::Rect& bounds) = 0;
   virtual gfx::Rect GetBounds() = 0;
 
   virtual void SetCapture() = 0;
   virtual void ReleaseCapture() = 0;
 
   virtual void ToggleFullscreen() = 0;
   virtual void Maximize() = 0;
   virtual void Minimize() = 0;
   virtual void Restore() = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_PLATFORM_WINDOW_PLATFORM_WINDOW_H_