Bug 1391733 - get back missing IAccessible2 interface query, r=aklotz

accessible/windows/ia2/ia2Accessible.cpp

@@ -46,6 +46,8 @@ ia2Accessible::QueryInterface(REFIID iid, void** ppv)
     *ppv = static_cast<IAccessible2_3*>(this);
   else if (IID_IAccessible2_2 == iid)
     *ppv = static_cast<IAccessible2_2*>(this);
+  else if (IID_IAccessible2 == iid)
+    *ppv = static_cast<IAccessible2*>(this);
 
   if (*ppv) {
     (reinterpret_cast<IUnknown*>(*ppv))->AddRef();