Fix leaking AXNodeObjects when sub document detaches

third_party/WebKit/Source/modules/accessibility/AXInlineTextBox.cpp

 /*
  * Copyright (C) 2013, Google 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 105 matching lines @@
 String AXInlineTextBox::stringValue() const
 {
     if (!m_inlineTextBox)
         return String();
 
     return m_inlineTextBox->text();
 }
 
 AXObject* AXInlineTextBox::computeParent() const
 {
+    ASSERT(!isDetached());
     if (!m_inlineTextBox || !m_axObjectCache)
         return 0;
 
     LayoutText* layoutText = m_inlineTextBox->layoutText();
     return m_axObjectCache->getOrCreate(layoutText);
 }
 
 // In addition to LTR and RTL direction, edit fields also support
 // top to bottom and bottom to top via the CSS writing-mode property.
 AccessibilityTextDirection AXInlineTextBox::textDirection() const
@@ skipping 33 matching lines @@
     if (previousOnLine)
         return m_axObjectCache->getOrCreate(previousOnLine.get());
 
     if (!m_inlineTextBox->isFirst())
         return 0;
 
     return parentObject()->previousOnLine();
 }
 
 } // namespace blink