diff -r 000000000000 -r 6474c204b198 accessible/src/windows/msaa/HTMLWin32ObjectAccessible.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/windows/msaa/HTMLWin32ObjectAccessible.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,92 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */
+
+#include "HTMLWin32ObjectAccessible.h"
+
+#include "Role.h"
+#include "States.h"
+
+using namespace mozilla::a11y;
+
+////////////////////////////////////////////////////////////////////////////////
+// HTMLWin32ObjectOwnerAccessible
+////////////////////////////////////////////////////////////////////////////////
+
+HTMLWin32ObjectOwnerAccessible::
+  HTMLWin32ObjectOwnerAccessible(nsIContent* aContent,
+                                 DocAccessible* aDoc, void* aHwnd) :
+  AccessibleWrap(aContent, aDoc), mHwnd(aHwnd)
+{
+  // Our only child is a HTMLWin32ObjectAccessible object.
+  if (mHwnd)
+    mNativeAccessible = new HTMLWin32ObjectAccessible(mHwnd);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// HTMLWin32ObjectOwnerAccessible: Accessible implementation
+
+void
+HTMLWin32ObjectOwnerAccessible::Shutdown()
+{
+  AccessibleWrap::Shutdown();
+  mNativeAccessible = nullptr;
+}
+
+role
+HTMLWin32ObjectOwnerAccessible::NativeRole()
+{
+  return roles::EMBEDDED_OBJECT;
+}
+
+bool
+HTMLWin32ObjectOwnerAccessible::NativelyUnavailable() const
+{
+  // XXX: No HWND means this is windowless plugin which is not accessible in
+  // the meantime.
+  return !mHwnd;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// HTMLWin32ObjectOwnerAccessible: Accessible protected implementation
+
+void
+HTMLWin32ObjectOwnerAccessible::CacheChildren()
+{
+  if (mNativeAccessible)
+    AppendChild(mNativeAccessible);
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+// HTMLWin32ObjectAccessible
+////////////////////////////////////////////////////////////////////////////////
+
+HTMLWin32ObjectAccessible::HTMLWin32ObjectAccessible(void* aHwnd) :
+  DummyAccessible()
+{
+  mHwnd = aHwnd;
+  if (mHwnd) {
+    // The plugin is not windowless. In this situation we use 
+    // use its inner child owned by the plugin so that we don't get
+    // in an infinite loop, where the WM_GETOBJECT's get forwarded
+    // back to us and create another HTMLWin32ObjectAccessible
+    HWND childWnd = ::GetWindow((HWND)aHwnd, GW_CHILD);
+    if (childWnd) {
+      mHwnd = childWnd;
+    }
+  }
+}
+
+NS_IMETHODIMP 
+HTMLWin32ObjectAccessible::GetNativeInterface(void** aNativeAccessible)
+{
+  if (mHwnd) {
+    ::AccessibleObjectFromWindow(static_cast<HWND>(mHwnd),
+                                 OBJID_WINDOW, IID_IAccessible,
+                                 aNativeAccessible);
+  }
+  return NS_OK;
+}
+