Adding the assert() that checks for the correct view source highlighting

Source/core/html/parser/HTMLToken.h

 /*
  * Copyright (C) 2013 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 312 matching lines @@
 
     void endAttributeValue(int offset)
     {
         m_currentAttribute->valueRange.end = offset - m_baseOffset;
     }
 
     void appendToAttributeName(UChar character)
     {
         ASSERT(character);
         ASSERT(m_type == StartTag || m_type == EndTag);
-        // FIXME: We should be able to add the following ASSERT once we fix
-        // https://bugs.webkit.org/show_bug.cgi?id=62971
-        //   ASSERT(m_currentAttribute->nameRange.start);
+        ASSERT(m_currentAttribute->nameRange.start);
         m_currentAttribute->name.append(character);
     }
 
     void appendToAttributeValue(UChar character)
     {
         ASSERT(character);
         ASSERT(m_type == StartTag || m_type == EndTag);
         ASSERT(m_currentAttribute->valueRange.start);
         m_currentAttribute->value.append(character);
     }
@@ skipping 106 matching lines @@
     // A pointer into m_attributes used during lexing.
     Attribute* m_currentAttribute;
 
     // For DOCTYPE
     OwnPtr<DoctypeData> m_doctypeData;
 };
 
 }
 
 #endif