Fast increment to the next inline renderer when the current renderer is isolated.

Source/core/rendering/RenderBlockLineLayout.cpp

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 378 matching lines @@
 }
 
 static TextDirection determinePlaintextDirectionality(RenderObject* root, RenderObject* current = 0, unsigned pos = 0)
 {
     InlineIterator iter(root, firstRenderObjectForDirectionalityDetermination(root, current), pos);
     InlineBidiResolver observer;
     observer.setPositionIgnoringNestedIsolates(iter);
     observer.setStatus(BidiStatus(root->style()->direction(), isOverride(root->style()->unicodeBidi())));
     while (!iter.atEnd()) {
         if (observer.inIsolate()) {
-            iter.increment(&observer);
+            iter.increment(&observer, InlineIterator::FastIncrementInlineRenderer);
             continue;
         }
         if (iter.atParagraphSeparator())
             break;
         if (UChar current = iter.current()) {
             Direction charDirection = direction(current);
             if (charDirection == LeftToRight)
                 return LTR;
             if (charDirection == RightToLeft || charDirection == RightToLeftArabic)
                 return RTL;
@@ skipping 3115 matching lines @@
     lineGridBox->alignBoxesInBlockDirection(logicalHeight(), textBoxDataMap, verticalPositionCache);
 
     setLineGridBox(lineGridBox);
 
     // FIXME: If any of the characteristics of the box change compared to the old one, then we need to do a deep dirtying
     // (similar to what happens when the page height changes). Ideally, though, we only do this if someone is actually snapping
     // to this grid.
 }
 
 }