Add a test that confirms there's no crash on accessing properties of AccesibilityObject at the init…

Source/core/accessibility/AXRenderObject.cpp

 /*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 779 matching lines @@
 String AXRenderObject::text() const
 {
     if (isPasswordField())
         return String();
 
     return AXNodeObject::text();
 }
 
 int AXRenderObject::textLength() const
 {
-    ASSERT(isTextControl());
+    if (!isTextControl())
+        return -1;
 
     if (isPasswordField())
         return -1; // need to return something distinct from 0
 
     return text().length();
 }
 
 KURL AXRenderObject::url() const
 {
     if (isAnchor() && isHTMLAnchorElement(m_renderer->node())) {
@@ skipping 750 matching lines @@
         return 0;
     return toRenderWidget(m_renderer)->widget();
 }
 
 //
 // Selected text.
 //
 
 AXObject::PlainTextRange AXRenderObject::selectedTextRange() const
 {
-    ASSERT(isTextControl());
+    if (!isTextControl())
+        return PlainTextRange();
 
     if (isPasswordField())
         return PlainTextRange();
 
     AccessibilityRole ariaRole = ariaRoleAttribute();
     if (isNativeTextControl() && ariaRole == UnknownRole && m_renderer->isTextControl()) {
         HTMLTextFormControlElement* textControl = toRenderTextControl(m_renderer)->textFormControlElement();
         return PlainTextRange(textControl->selectionStart(), textControl->selectionEnd() - textControl->selectionStart());
     }
 
@@ skipping 760 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace WebCore