Add RELEASE_ASSERT to InlineTextBox::constructTextRun

third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple 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 598 matching lines @@
 }
 
 TextRun InlineTextBox::constructTextRun(
     const ComputedStyle& style,
     StringBuilder* charactersWithHyphen) const {
   ASSERT(getLineLayoutItem().text());
 
   String string = getLineLayoutItem().text();
   unsigned startPos = start();
   unsigned length = len();
+  // Ensure |this| is in sync with the corresponding LayoutText. Checking here
+  // has less binary size/perf impact than in StringView().
+  RELEASE_ASSERT(startPos <= string.length() &&
+                 length <= string.length() - startPos);
   return constructTextRun(style, StringView(string, startPos, length),
                           getLineLayoutItem().textLength() - startPos,
                           charactersWithHyphen);
 }
 
 TextRun InlineTextBox::constructTextRun(
     const ComputedStyle& style,
     StringView string,
     int maximumLength,
     StringBuilder* charactersWithHyphen) const {
@@ skipping 54 matching lines @@
   const int layoutObjectCharacterOffset = 75;
   for (; printedCharacters < layoutObjectCharacterOffset; printedCharacters++)
     fputc(' ', stderr);
   fprintf(stderr, "(%d,%d) \"%s\"\n", start(), start() + len(),
           value.utf8().data());
 }
 
 #endif
 
 }  // namespace blink