Update BidiResolver's max level depth to 125 per tr9r29

Source/platform/text/BidiContext.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2009, 2010 Apple Inc. All right 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 30 matching lines @@
 public:
     static PassRefPtr<BidiContext> create(unsigned char level, WTF::Unicode::Direction, bool override = false, BidiEmbeddingSource = FromStyleOrDOM, BidiContext* parent = 0);
 
     BidiContext* parent() const { return m_parent.get(); }
     unsigned char level() const { return m_level; }
     WTF::Unicode::Direction dir() const { return static_cast<WTF::Unicode::Direction>(m_direction); }
     bool override() const { return m_override; }
     BidiEmbeddingSource source() const { return static_cast<BidiEmbeddingSource>(m_source); }
 
     PassRefPtr<BidiContext> copyStackRemovingUnicodeEmbeddingContexts();
+
+    // http://www.unicode.org/reports/tr9/#Modifications
+    // 6.3 raised the limit from 61 to 125.
+    // http://unicode.org/reports/tr9/#BD2
+    static const unsigned char kMaxLevel = 125;
+
 private:
     BidiContext(unsigned char level, WTF::Unicode::Direction direction, bool override, BidiEmbeddingSource source, BidiContext* parent)
         : m_level(level)
         , m_direction(direction)
         , m_override(override)
         , m_source(source)
         , m_parent(parent)
     {
+        ASSERT(level <= kMaxLevel);
     }
 
     static PassRefPtr<BidiContext> createUncached(unsigned char level, WTF::Unicode::Direction, bool override, BidiEmbeddingSource, BidiContext* parent);
 
-    unsigned m_level : 6; // The maximium bidi level is 62: http://unicode.org/reports/tr9/#Explicit_Levels_and_Directions
+    unsigned m_level : 7; // The maximium bidi level is 125: http://unicode.org/reports/tr9/#Explicit_Levels_and_Directions
     unsigned m_direction : 5; // Direction
     unsigned m_override : 1;
     unsigned m_source : 1; // BidiEmbeddingSource
     RefPtr<BidiContext> m_parent;
 };
 
 inline unsigned char nextGreaterOddLevel(unsigned char level)
 {
     return (level + 1) | 1;
 }
 
 inline unsigned char nextGreaterEvenLevel(unsigned char level)
 {
     return (level + 2) & ~1;
 }
 
 PLATFORM_EXPORT bool operator==(const BidiContext&, const BidiContext&);
 
 } // namespace WebCore
 
 #endif // BidiContext_h