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

Source/core/css/analyzer/DescendantInvalidationSet.cpp

Index: Source/core/css/analyzer/DescendantInvalidationSet.cpp
diff --git a/Source/core/svg/SVGAnimatedLength.cpp b/Source/core/css/analyzer/DescendantInvalidationSet.cpp
similarity index 54%
copy from Source/core/svg/SVGAnimatedLength.cpp
copy to Source/core/css/analyzer/DescendantInvalidationSet.cpp
index bc447b07280ebfb8d410374e1bd403a14d4851cc..6249f197e84095c9c95f51e3d1ec75114840cdb6 100644
--- a/Source/core/svg/SVGAnimatedLength.cpp
+++ b/Source/core/css/analyzer/DescendantInvalidationSet.cpp
@@ -29,28 +29,51 @@
  */
 
 #include "config.h"
+#include "core/css/analyzer/DescendantInvalidationSet.h"
 
-#include "core/svg/SVGAnimatedLength.h"
+#include "core/css/resolver/StyleResolver.h"
+#include "core/dom/Element.h"
 
 namespace WebCore {
 
-void SVGAnimatedLength::setDefaultValueAsString(const String& value)
+DescendantInvalidationSet::DescendantInvalidationSet()
+    : m_allDescendantsMightBeInvalid(false)
 {
-    baseValue()->setValueAsString(value, ASSERT_NO_EXCEPTION);
 }
 
-void SVGAnimatedLength::setBaseValueAsString(const String& value, SVGLengthNegativeValuesMode mode, SVGParsingError& parseError)
+void DescendantInvalidationSet::combine(const DescendantInvalidationSet& other)
 {
-    TrackExceptionState es;
+    m_allDescendantsMightBeInvalid = m_allDescendantsMightBeInvalid || other.m_allDescendantsMightBeInvalid;
+    // No longer bother combining data structures, since the whole subtree is deemed invalid.
+    if (m_allDescendantsMightBeInvalid)
+        return;
 
-    baseValue()->setValueAsString(value, es);
+    HashSet<AtomicString>::const_iterator end = other.m_classes.end();
+    for (HashSet<AtomicString>::const_iterator it = other.m_classes.begin(); it != end; ++it)
+        addClass(*it);
 
-    if (es.hadException()) {
-        parseError = ParsingAttributeFailedError;
-        baseValue()->newValueSpecifiedUnits(LengthTypeNumber, 0);
-    } else if (mode == ForbidNegativeLengths && baseValue()->valueInSpecifiedUnits() < 0) {
-        parseError = NegativeValueForbiddenError;
-    }
+    end = other.m_ids.end();
+    for (HashSet<AtomicString>::const_iterator it = other.m_ids.begin(); it != end; ++it)
+        addId(*it);
+
+    end = other.m_tagNames.end();
+    for (HashSet<AtomicString>::const_iterator it = other.m_tagNames.begin(); it != end; ++it)
+        addTagName(*it);
 }
 
+void DescendantInvalidationSet::addClass(const AtomicString& className)
+{
+    m_classes.add(className);
+}
+
+void DescendantInvalidationSet::addId(const AtomicString& id)
+{
+    m_ids.add(id);
 }
+
+void DescendantInvalidationSet::addTagName(const AtomicString& tagName)
+{
+    m_tagNames.add(tagName);
+}
+
+} // namespace WebCore