Add a first pass of a class descendant invalidator, and a containing RuleSetAnalyzer

Source/core/css/analyzer/RuleSetAnalyzer.h

Index: Source/core/css/analyzer/RuleSetAnalyzer.h
diff --git a/Source/core/svg/SVGAnimatedLength.h b/Source/core/css/analyzer/RuleSetAnalyzer.h
similarity index 64%
copy from Source/core/svg/SVGAnimatedLength.h
copy to Source/core/css/analyzer/RuleSetAnalyzer.h
index 36efeb08d1e17fe2c1615d9c4d22d4f31978fd32..14cfebfa2d7f9d06a3b5e92edf708387f72952c2 100644
--- a/Source/core/svg/SVGAnimatedLength.h
+++ b/Source/core/css/analyzer/RuleSetAnalyzer.h
@@ -28,31 +28,36 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef SVGAnimatedLength_h
-#define SVGAnimatedLength_h
+#ifndef RuleSetAnalyzer_h
+#define RuleSetAnalyzer_h
 
-#include "core/svg/SVGLengthTearOff.h"
-#include "core/svg/properties/NewSVGAnimatedProperty.h"
+#include "core/css/analyzer/DescendantInvalidationSet.h"
+#include "wtf/RefCounted.h"
 
 namespace WebCore {
 
-class SVGAnimatedLength : public NewSVGAnimatedProperty<SVGLength> {
+class CSSSelector;
+class RuleFeatureSet;
+class RuleData;
+
+// Keeps track of information about a set of CSS rules in order to answer style questions about them.
+class RuleSetAnalyzer : public RefCounted<RuleSetAnalyzer> {
 public:
-    static PassRefPtr<SVGAnimatedLength> create(SVGElement* contextElement, const QualifiedName& attributeName, PassRefPtr<SVGLength> initialValue)
-    {
-        return adoptRef(new SVGAnimatedLength(contextElement, attributeName, initialValue));
-    }
-
-    void setDefaultValueAsString(const String&);
-    void setBaseValueAsString(const String&, SVGLengthNegativeValuesMode, SVGParsingError&);
-
-protected:
-    SVGAnimatedLength(SVGElement* contextElement, const QualifiedName& attributeName, PassRefPtr<SVGLength> initialValue)
-        : NewSVGAnimatedProperty<SVGLength>(contextElement, attributeName, initialValue)
-    {
-    }
+    static PassRefPtr<RuleSetAnalyzer> create();
+
+    void collectFeaturesFromRuleData(RuleFeatureSet& features, const RuleData&);
+    void combine(const RuleSetAnalyzer& other);
+private:
+    RuleSetAnalyzer();
+    typedef HashMap<AtomicString, RefPtr<DescendantInvalidationSet> > InvalidationSetMap;
+
+    DescendantInvalidationSet* ensureClassInvalidationSet(const AtomicString& className);
+
+    bool updateClassInvalidationSets(const CSSSelector*);
+
+    InvalidationSetMap m_classInvalidationSets;
 };
 
 } // namespace WebCore
 
-#endif // SVGAnimatedLength_h
+#endif // RuleSetAnalyzer_h