Do not report some CSS errors for code valid in other browsers.

Source/core/css/CSSParserValues.h

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008, 2009, 2010 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 83 matching lines @@
     bool equalIgnoringCase(const char* str) const
     {
         if (is8Bit())
             return WTF::equalIgnoringCase(str, characters8(), length());
         return WTF::equalIgnoringCase(str, characters16(), length());
     }
 
     template <size_t strLength>
     bool startsWithIgnoringCase(const char (&str)[strLength]) const
     {
-        return startsWithIgnoringCase(str, strLength - 1);
+        return containsIgnoringCaseAt(str, strLength - 1, 0);
     }
 
-    bool startsWithIgnoringCase(const char* str, size_t strLength) const
+    template <size_t strLength>
+    bool containsIgnoringCaseAt(const char (&str)[strLength], unsigned offset) const
     {
-        if (length() < strLength)
+        return containsIgnoringCaseAt(str, strLength - 1, offset);
+    }
+
+    bool containsIgnoringCaseAt(const char* str, size_t strLength, unsigned offset) const
+    {
+        if (length() < strLength + offset)
             return false;
-        return is8Bit() ? WTF::equalIgnoringCase(str, characters8(), strLength) : WTF::equalIgnoringCase(str, characters16(), strLength);
+        return is8Bit() ? WTF::equalIgnoringCase(str, characters8() + offset, strLength) : WTF::equalIgnoringCase(str, characters16() + offset, strLength);
     }
 
     operator String() const { return is8Bit() ? String(m_data.characters8, m_length) : String(m_data.characters16, m_length); }
     operator AtomicString() const { return is8Bit() ? AtomicString(m_data.characters8, m_length) : AtomicString(m_data.characters16, m_length); }
 
     AtomicString atomicSubstring(unsigned position, unsigned length) const;
 
     union {
         const LChar* characters8;
         const UChar* characters16;
@@ skipping 128 matching lines @@
 inline void CSSParserValue::setFromFunction(CSSParserFunction* function)
 {
     id = CSSValueInvalid;
     this->function = function;
     unit = Function;
 }
 
 }
 
 #endif