Move HTMLDocument::isCaseSensitiveAttribute into SelectorChecker

third_party/WebKit/Source/core/css/SelectorChecker.cpp

Index: third_party/WebKit/Source/core/css/SelectorChecker.cpp
diff --git a/third_party/WebKit/Source/core/css/SelectorChecker.cpp b/third_party/WebKit/Source/core/css/SelectorChecker.cpp
index fa6b7bb954278be35d95d5e62149a88f1cd3999d..c85fc1ec1f5a9142ca0c7e7de10350f4bf413d39 100644
--- a/third_party/WebKit/Source/core/css/SelectorChecker.cpp
+++ b/third_party/WebKit/Source/core/css/SelectorChecker.cpp
@@ -497,6 +497,42 @@ static bool attributeValueMatches(const Attribute& attributeItem, CSSSelector::M
     }
 }
 
+static HashSet<StringImpl*>* createHtmlCaseInsensitiveAttributesSet()
+{
+    // This list of attributes is from
+    // https://html.spec.whatwg.org/#case-sensitivity-of-selectors
+    HashSet<StringImpl*>* attrSet = new HashSet<StringImpl*>;
+
+    const QualifiedName* caseInsensitiveAttributes[] = {
+        &accept_charsetAttr, &acceptAttr, &alignAttr, &alinkAttr, &axisAttr,
+        &bgcolorAttr,
+        &charsetAttr, &checkedAttr, &clearAttr, &codetypeAttr, &colorAttr, &compactAttr,
+        &declareAttr, &deferAttr, &dirAttr, &directionAttr, &disabledAttr,
+        &enctypeAttr,
+        &faceAttr, &frameAttr,
+        &hreflangAttr, &http_equivAttr,
+        &langAttr, &languageAttr, &linkAttr,
+        &mediaAttr, &methodAttr, &multipleAttr,
+        &nohrefAttr, &noresizeAttr, &noshadeAttr, &nowrapAttr,
+        &readonlyAttr, &relAttr, &revAttr, &rulesAttr,
+        &scopeAttr, &scrollingAttr, &selectedAttr, &shapeAttr,
+        &targetAttr, &textAttr, &typeAttr,
+        &valignAttr, &valuetypeAttr, &vlinkAttr };
+
+    attrSet->reserveCapacityForSize(WTF_ARRAY_LENGTH(caseInsensitiveAttributes));
+    for (const QualifiedName* attr : caseInsensitiveAttributes)
+        attrSet->add(attr->localName().impl());
+
+    return attrSet;
+}
+
+static bool isHtmlCaseSensitiveAttribute(const QualifiedName& attributeName)
+{
+    static HashSet<StringImpl*>* htmlCaseInsensitiveAttributesSet = createHtmlCaseInsensitiveAttributesSet();
+    bool isPossibleHTMLAttr = !attributeName.hasPrefix() && (attributeName.namespaceURI() == nullAtom);
+    return !isPossibleHTMLAttr || !htmlCaseInsensitiveAttributesSet->contains(attributeName.localName().impl());
+}
+
 static bool anyAttributeMatches(Element& element, CSSSelector::MatchType match, const CSSSelector& selector)
 {
     const QualifiedName& selectorAttr = selector.attribute();
@@ -523,10 +559,10 @@ static bool anyAttributeMatches(Element& element, CSSSelector::MatchType match,
             continue;
         }
 
-        // Legacy dictates that values of some attributes should be compared in
-        // a case-insensitive manner regardless of whether the case insensitive
-        // flag is set or not.
-        bool legacyCaseInsensitive = element.document().isHTMLDocument() && !HTMLDocument::isCaseSensitiveAttribute(selectorAttr);
+        // https://html.spec.whatwg.org/#case-sensitivity-of-selectors
+        // TODO(foolip): The spec says "HTML element in an HTML document", but
+        // this applies to any element in an HTML document.
+        bool legacyCaseInsensitive = element.document().isHTMLDocument() && !isHtmlCaseSensitiveAttribute(selectorAttr);
 
         // If case-insensitive, re-check, and count if result differs.
         // See http://code.google.com/p/chromium/issues/detail?id=327060