Revert "views: Move widget/ directory to ui/views." properly.

views/widget/native_widget.h

+// Copyright (c) 2011 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 VIEWS_WIDGET_NATIVE_WIDGET_H_
+#define VIEWS_WIDGET_NATIVE_WIDGET_H_
+#pragma once
+
+#include "views/widget/widget.h"
+
+namespace views {
+namespace internal {
+class NativeWidgetPrivate;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// NativeWidget interface
+//
+//  An interface that serves as the public API base for the
+//  internal::NativeWidget interface that Widget uses to communicate with a
+//  backend-specific native widget implementation. This is the only component of
+//  this interface that is publicly visible, and exists solely for exposure via
+//  Widget's native_widget() accessor, which code occasionally static_casts to
+//  a known implementation in platform-specific code.
+//
+class VIEWS_EXPORT NativeWidget {
+ public:
+  virtual ~NativeWidget() {}
+
+ private:
+  friend class Widget;
+
+  virtual internal::NativeWidgetPrivate* AsNativeWidgetPrivate() = 0;
+};
+
+}  // namespace views
+
+#endif  // VIEWS_WIDGET_NATIVE_WIDGET_H_