Add support for element ids in TargetedStyleRecalc

Source/core/css/RuleFeature.cpp

Index: Source/core/css/RuleFeature.cpp
diff --git a/Source/core/css/RuleFeature.cpp b/Source/core/css/RuleFeature.cpp
index 33b5ed35496d04b053c91f7e56daef4bafc9844e..a767562d88f6348c21cd985e3708b8be866a4949 100644
--- a/Source/core/css/RuleFeature.cpp
+++ b/Source/core/css/RuleFeature.cpp
@@ -109,8 +109,8 @@ RuleFeatureSet::InvalidationSetMode RuleFeatureSet::supportsClassDescendantInval
     bool foundIdent = false;
     for (const CSSSelector* component = &selector; component; component = component->tagHistory()) {
 
-        // FIXME: next up: Tag and Id.
-        if (component->m_match == CSSSelector::Class || component->isAttributeSelector() || component->isCustomPseudoElement()) {
+        // FIXME: next up: Tag.
+        if (component->m_match == CSSSelector::Class || component->m_match == CSSSelector::Id || component->isAttributeSelector() || component->isCustomPseudoElement()) {
             if (!foundDescendantRelation)
                 foundIdent = true;
         } else if (component->pseudoType() == CSSSelector::PseudoHost || component->pseudoType() == CSSSelector::PseudoAny) {
@@ -167,6 +167,8 @@ DescendantInvalidationSet* RuleFeatureSet::invalidationSetForSelector(const CSSS
         return &ensureClassInvalidationSet(selector.value());
     if (selector.isAttributeSelector())
         return &ensureAttributeInvalidationSet(selector.attribute().localName());
+    if (selector.m_match == CSSSelector::Id)
+        return &ensureIdInvalidationSet(selector.value());
     return 0;
 }
 
@@ -266,6 +268,15 @@ DescendantInvalidationSet& RuleFeatureSet::ensureAttributeInvalidationSet(const
         addResult.storedValue->value = DescendantInvalidationSet::create();
     return *addResult.storedValue->value;
 }
+
+DescendantInvalidationSet& RuleFeatureSet::ensureIdInvalidationSet(const AtomicString& id)
+{
+    InvalidationSetMap::AddResult addResult = m_idInvalidationSets.add(id, nullptr);
+    if (addResult.isNewEntry)
+        addResult.storedValue->value = DescendantInvalidationSet::create();
+    return *addResult.storedValue->value;
+}
+
 void RuleFeatureSet::collectFeaturesFromSelector(const CSSSelector& selector)
 {
     collectFeaturesFromSelector(selector, m_metadata, UseSubtreeStyleChange);
@@ -276,9 +287,7 @@ void RuleFeatureSet::collectFeaturesFromSelector(const CSSSelector& selector, Ru
     unsigned maxDirectAdjacentSelectors = 0;
 
     for (const CSSSelector* current = &selector; current; current = current->tagHistory()) {
-        if (current->m_match == CSSSelector::Id) {
-            metadata.idsInRules.add(current->value());
-        } else if (mode != AddFeatures && (current->m_match == CSSSelector::Class || current->isAttributeSelector())) {
+        if (mode != AddFeatures && (current->m_match == CSSSelector::Class || current->m_match == CSSSelector::Id || current->isAttributeSelector())) {
             DescendantInvalidationSet* invalidationSet = invalidationSetForSelector(*current);
             ASSERT(invalidationSet);
             if (mode == UseSubtreeStyleChange)
@@ -318,15 +327,10 @@ void RuleFeatureSet::FeatureMetadata::add(const FeatureMetadata& other)
 {
     usesFirstLineRules = usesFirstLineRules || other.usesFirstLineRules;
     maxDirectAdjacentSelectors = std::max(maxDirectAdjacentSelectors, other.maxDirectAdjacentSelectors);
-
-    HashSet<AtomicString>::const_iterator end = other.idsInRules.end();
-    for (HashSet<AtomicString>::const_iterator it = other.idsInRules.begin(); it != end; ++it)
-        idsInRules.add(*it);
 }
 
 void RuleFeatureSet::FeatureMetadata::clear()
 {
-    idsInRules.clear();
     usesFirstLineRules = false;
     foundSiblingSelector = false;
     maxDirectAdjacentSelectors = 0;
@@ -338,6 +342,8 @@ void RuleFeatureSet::add(const RuleFeatureSet& other)
         ensureClassInvalidationSet(it->key).combine(*it->value);
     for (InvalidationSetMap::const_iterator it = other.m_attributeInvalidationSets.begin(); it != other.m_attributeInvalidationSets.end(); ++it)
         ensureAttributeInvalidationSet(it->key).combine(*it->value);
+    for (InvalidationSetMap::const_iterator it = other.m_idInvalidationSets.begin(); it != other.m_idInvalidationSets.end(); ++it)
+        ensureIdInvalidationSet(it->key).combine(*it->value);
 
     m_metadata.add(other.m_metadata);
 
@@ -352,6 +358,7 @@ void RuleFeatureSet::clear()
     m_metadata.clear();
     m_classInvalidationSets.clear();
     m_attributeInvalidationSets.clear();
+    m_idInvalidationSets.clear();
     m_styleInvalidator.clearPendingInvalidations();
 }
 
@@ -402,6 +409,18 @@ void RuleFeatureSet::scheduleStyleInvalidationForAttributeChange(const Qualified
         m_styleInvalidator.scheduleInvalidation(invalidationSet, element);
 }
 
+void RuleFeatureSet::scheduleStyleInvalidationForIdChange(const AtomicString& oldId, const AtomicString& newId, Element& element)
+{
+    if (!oldId.isEmpty()) {
+        if (RefPtr<DescendantInvalidationSet> invalidationSet = m_idInvalidationSets.get(oldId))
+            m_styleInvalidator.scheduleInvalidation(invalidationSet, element);
+    }
+    if (!newId.isEmpty()) {
+        if (RefPtr<DescendantInvalidationSet> invalidationSet = m_idInvalidationSets.get(newId))
+            m_styleInvalidator.scheduleInvalidation(invalidationSet, element);
+    }
+}
+
 void RuleFeatureSet::addClassToInvalidationSet(const AtomicString& className, Element& element)
 {
     if (RefPtr<DescendantInvalidationSet> invalidationSet = m_classInvalidationSets.get(className))