Set autofilled property to false when edit the autofilled text in textarea

Source/core/html/HTMLTextAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 252 matching lines @@
 {
     if (LocalFrame* frame = document().frame())
         frame->spellChecker().didBeginEditing(this);
 }
 
 void HTMLTextAreaElement::subtreeHasChanged()
 {
     setChangedSinceLastFormControlChangeEvent(true);
     m_valueIsUpToDate = false;
     setNeedsValidityCheck();
+    setAutofilled(false);
 
     if (!focused())
         return;
 
     // When typing in a textarea, childrenChanged is not called, so we need to force the directionality check.
     calculateAndAdjustDirectionality();
 
     ASSERT(document().isActive());
     document().frameHost()->chrome().client().didChangeValueInTextField(*this);
 }
@@ skipping 282 matching lines @@
 {
     return true;
 }
 
 bool HTMLTextAreaElement::supportsAutofocus() const
 {
     return true;
 }
 
 }