Make SpellChecker::didBeginEdit() not to crash with IFRAME parameter

third_party/WebKit/Source/core/editing/spellcheck/SpellChecker.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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 122 matching lines @@
         if (isHTMLTextFormControlElement(*element)) {
             HTMLTextFormControlElement* textControl = toHTMLTextFormControlElement(element);
             parent = textControl;
             element = textControl->innerEditorElement();
             if (!element)
                 return;
             isTextField = isHTMLInputElement(*textControl) && toHTMLInputElement(*textControl).isTextField();
         }
 
         if (isTextField || !parent->isAlreadySpellChecked()) {
+            if (EditingStrategy::editingIgnoresContent(element))

[yoichio, 2016/06/29 01:35:57]

Please add description why crash happens and this line solves that issue.

[yosin_UTC9, 2016/06/29 02:03:04]

Done.

+                return;
             // We always recheck textfields because markers are removed from them on blur.
             VisibleSelection selection = VisibleSelection::selectionFromContentsOfNode(element);
             markMisspellingsAndBadGrammar(selection);
             if (!isTextField)
                 parent->setAlreadySpellChecked(true);
         }
     }
 }
 
 void SpellChecker::ignoreSpelling()
@@ skipping 802 matching lines @@
     visitor->trace(m_frame);
     visitor->trace(m_spellCheckRequester);
 }
 
 void SpellChecker::prepareForLeakDetection()
 {
     m_spellCheckRequester->prepareForLeakDetection();
 }
 
 } // namespace blink