Introduce use counters for shadow DOM handling in plainText()

Source/core/editing/iterators/CharacterIterator.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov.
  *
  * 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 610 matching lines @@
     resultEnd.clear();
     // CharacterIterator requires layoutObjects to be up-to-date.
     if (!inputStart.inDocument())
         return;
     ASSERT(inputStart.document() == inputEnd.document());
 
     // FIXME: Reduce the code duplication with above (but how?).
     size_t matchStart;
     size_t matchLength;
     {
-        CharacterIterator findIterator(inputStart, inputEnd, iteratorFlagsForFindPlainText);
+        TextIteratorBehaviorFlags behavior = iteratorFlagsForFindPlainText;
+        if (options & FindAPICall)
+            behavior |= TextIteratorForWindowFind;
+        CharacterIterator findIterator(inputStart, inputEnd, behavior);
         matchLength = findPlainTextInternal(findIterator, target, options, matchStart);
         if (!matchLength) {
             const Position& collapseTo = options & Backwards ? inputStart : inputEnd;
             resultStart = collapseTo;
             resultEnd = collapseTo;
             return;
         }
     }
 
     CharacterIterator computeRangeIterator(inputStart, inputEnd, iteratorFlagsForFindPlainText);
     computeRangeIterator.calculateCharacterSubrange(matchStart, matchLength, resultStart, resultEnd);
 }
 
 } // namespace blink