Custom frame UI for platform apps on Windows.

chrome/browser/ui/extensions/native_shell_frame.h

+// Copyright (c) 2012 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 CHROME_BROWSER_UI_EXTENSIONS_NATIVE_SHELL_FRAME_H_
+#define CHROME_BROWSER_UI_EXTENSIONS_NATIVE_SHELL_FRAME_H_
+#pragma once
+
+namespace views {
+  class NativeWidget;
+  class Widget;
+}
+
+class NativeShellFrame {
+ public:
+  virtual ~NativeShellFrame() {}
+
+  // Construct a platform-specific implementation of this interface.
+  static NativeShellFrame* CreateNativeShellFrame(
+      views::Widget* container);
+
+  virtual views::NativeWidget* AsNativeWidget() = 0;
+  virtual const views::NativeWidget* AsNativeWidget() const = 0;
+};
+
+#endif  // CHROME_BROWSER_UI_EXTENSIONS_NATIVE_SHELL_FRAME_H_