Oilpan: promptly dispose style resolvers upon clearing.

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

Index: third_party/WebKit/Source/core/css/RuleSet.cpp
diff --git a/third_party/WebKit/Source/core/css/RuleSet.cpp b/third_party/WebKit/Source/core/css/RuleSet.cpp
index b0572ea07a6bcb5492c6526769d7c475a11ea63f..c46e2fe98139c85dbfe4b30d6954667734ad955b 100644
--- a/third_party/WebKit/Source/core/css/RuleSet.cpp
+++ b/third_party/WebKit/Source/core/css/RuleSet.cpp
@@ -119,6 +119,33 @@ RuleData::RuleData(StyleRule* rule, unsigned selectorIndex, unsigned position, A
     SelectorFilter::collectIdentifierHashes(selector(), m_descendantSelectorIdentifierHashes, maximumIdentifierCount);
 }
 
+RuleSet::~RuleSet()
+{
+}
+
+#if ENABLE(OILPAN)
+void RuleSet::dispose()
+{
+    m_idRules.clear();
+    m_classRules.clear();
+    m_tagRules.clear();
+    m_shadowPseudoElementRules.clear();
+    m_linkPseudoClassRules.clear();
+    m_cuePseudoRules.clear();
+    m_focusPseudoClassRules.clear();
+    m_universalRules.clear();
+    m_shadowHostRules.clear();
+    m_features.clear();
+    m_pageRules.clear();
+    m_viewportRules.clear();
+    m_fontFaceRules.clear();
+    m_keyframesRules.clear();
+    m_treeBoundaryCrossingRules.clear();
+    m_shadowDistributedRules.clear();
+    m_pendingRules.clear();
+}
+#endif
+
 void RuleSet::addToRuleSet(const AtomicString& key, PendingRuleMap& map, const RuleData& ruleData)
 {
     OwnPtrWillBeMember<WillBeHeapLinkedStack<RuleData>>& rules = map.add(key, nullptr).storedValue->value;