Add clean layout DCHECK to mostBackwardCaretPosition()

third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009, 2010, 2011 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 235 matching lines @@
   removeInterchangeNodes(holder);
   removeUnrenderedNodes(holder);
   restoreAndRemoveTestRenderingNodesToFragment(holder);
 
   // Give the root a chance to change the text.
   BeforeTextInsertedEvent* evt = BeforeTextInsertedEvent::create(text);
   editableRoot->dispatchEvent(evt);
   if (text != evt->text() || !hasRichlyEditableStyle(*editableRoot)) {
     restoreAndRemoveTestRenderingNodesToFragment(holder);
 
+    // TODO(editing-dev): Use of updateStyleAndLayoutIgnorePendingStylesheets
+    // needs to be audited.  See http://crbug.com/590369 for more details.
+    document->updateStyleAndLayoutIgnorePendingStylesheets();
+
     m_fragment = createFragmentFromText(selection.toNormalizedEphemeralRange(),
                                         evt->text());
     if (!m_fragment->hasChildren())
       return;
 
     holder = insertFragmentForTestRendering(editableRoot);
     removeInterchangeNodes(holder);
     removeUnrenderedNodes(holder);
     restoreAndRemoveTestRenderingNodesToFragment(holder);
   }
@@ skipping 1754 matching lines @@
   visitor->trace(m_startOfInsertedContent);
   visitor->trace(m_endOfInsertedContent);
   visitor->trace(m_insertionStyle);
   visitor->trace(m_documentFragment);
   visitor->trace(m_startOfInsertedRange);
   visitor->trace(m_endOfInsertedRange);
   CompositeEditCommand::trace(visitor);
 }
 
 }  // namespace blink