diff -r 000000000000 -r 6474c204b198 accessible/src/windows/msaa/nsWinUtils.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/windows/msaa/nsWinUtils.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsWinUtils_h_
+#define nsWinUtils_h_
+
+#include <windows.h>
+
+#include "nsIDOMCSSStyleDeclaration.h"
+#include "nsCOMPtr.h"
+#include "nsRefPtrHashtable.h"
+
+class nsIArray;
+class nsIContent;
+
+namespace mozilla {
+namespace a11y {
+
+class DocAccessible;
+
+const LPCWSTR kClassNameRoot = L"MozillaUIWindowClass";
+const LPCWSTR kClassNameTabContent = L"MozillaContentWindowClass";
+
+class nsWinUtils
+{
+public:
+  /**
+   * Return computed styles declaration for the given node.
+   *
+   * @note Please use it carefully since it can shutdown the accessible tree
+   *       you operate on.
+   */
+  static already_AddRefed<nsIDOMCSSStyleDeclaration>
+    GetComputedStyleDeclaration(nsIContent* aContent);
+
+  /**
+   * Start window emulation if presence of specific AT is detected.
+   */
+  static bool MaybeStartWindowEmulation();
+
+  /**
+   * Free resources used for window emulation.
+   */
+  static void ShutdownWindowEmulation();
+
+  /**
+   * Return true if window emulation is started.
+   */
+  static bool IsWindowEmulationStarted();
+
+  /**
+   * Helper to register window class.
+   */
+  static void RegisterNativeWindow(LPCWSTR aWindowClass);
+
+  /**
+   * Helper to create a window.
+   */
+  static HWND CreateNativeWindow(LPCWSTR aWindowClass, HWND aParentWnd,
+                                 int aX, int aY, int aWidth, int aHeight,
+                                 bool aIsActive);
+
+  /**
+   * Helper to show window.
+   */
+  static void ShowNativeWindow(HWND aWnd);
+
+  /**
+   * Helper to hide window.
+   */
+  static void HideNativeWindow(HWND aWnd);
+
+  /**
+   * Cache for HWNDs of windows created for document accessibles in windows
+   * emulation mode.
+   */
+  static nsRefPtrHashtable<nsPtrHashKey<void>, DocAccessible>* sHWNDCache;
+};
+
+} // namespace a11y
+} // namespace mozilla
+
+#endif