Add support for case-insensitive attribute value selectors

Source/core/css/parser/BisonCSSParser-in.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 1092 matching lines @@
 
     // can't use { because tokenizer state switches from mediaquery to initial state when it sees { token.
     // instead insert one " " (which is caught by maybe_space in CSSGrammar.y)
     setupParser("@-internal-medialist ", string, "");
     cssyyparse(this);
 
     ASSERT(m_mediaList);
     return m_mediaList.release();
 }
 
+bool BisonCSSParser::parseAttributeMatchType(CSSSelector::AttributeMatchType& matchType, const String& string)
+{
+    if (!RuntimeEnabledFeatures::cssAttributeCaseSensitivityEnabled() && !isUASheetBehavior(m_context.mode()))
+        return false;
+    if (string == "i") {

[eseidel, 2014/07/30 20:12:41]

Why are we going through a string type here?

[fs, 2014/07/31 09:27:15]

Because of one of the following I suppose:
1) there's no operator==(const String&, char)
2) it's more readable than the open-coded version (string.length() == 1 &&
string[0] == 'i')

If you meant s/string type/WTF::String type/, then the answer is "we don't",
because there is an operator== overload for this case (so this compiles to a
call to WTF::equal(const StringImpl*, const LChar*).)

+        matchType = CSSSelector::CaseInsensitive;
+        return true;
+    }
+    return false;
+}
+
 static inline void filterProperties(bool important, const WillBeHeapVector<CSSProperty, 256>& input, WillBeHeapVector<CSSProperty, 256>& output, size_t& unusedEntries, BitArray<numCSSProperties>& seenProperties)
 {
     // Add properties in reverse order so that highest priority definitions are reached first. Duplicate definitions can then be ignored when found.
     for (int i = input.size() - 1; i >= 0; --i) {
         const CSSProperty& property = input[i];
         if (property.isImportant() != important)
             continue;
         const unsigned propertyIDIndex = property.id() - firstCSSProperty;
         if (seenProperties.get(propertyIDIndex))
             continue;
@@ skipping 971 matching lines @@
     rule->setProperties(createStylePropertySet());
     clearProperties();
 
     StyleRuleViewport* result = rule.get();
     m_parsedRules.append(rule.release());
 
     return result;
 }
 
 }