Oilpan: promptly dispose style resolvers upon clearing.

third_party/WebKit/Source/core/css/resolver/ScopedStyleResolver.cpp

Index: third_party/WebKit/Source/core/css/resolver/ScopedStyleResolver.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/ScopedStyleResolver.cpp b/third_party/WebKit/Source/core/css/resolver/ScopedStyleResolver.cpp
index 731252ae344cbe14f5a9a6329b3abc8fd2771a73..358875b80b8b611ca7ad6958f6d9bcc743459e8a 100644
--- a/third_party/WebKit/Source/core/css/resolver/ScopedStyleResolver.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/ScopedStyleResolver.cpp
@@ -46,6 +46,24 @@
 
 namespace blink {
 
+#if ENABLE(OILPAN)
+void ScopedStyleResolver::dispose()
+{
+    m_keyframesRuleMap.clear();
+
+    if (m_treeBoundaryCrossingRuleSet) {
+        for (size_t i = 0; i < m_treeBoundaryCrossingRuleSet->size(); ++i) {
+            if (RuleSet* ruleSet = m_treeBoundaryCrossingRuleSet->at(i)->m_ruleSet.get())
+                ruleSet->dispose();
+        }
+
+        m_treeBoundaryCrossingRuleSet->clear();
+        m_treeBoundaryCrossingRuleSet.clear();
+    }
+
+}
+#endif
+
 ScopedStyleResolver* ScopedStyleResolver::parent() const
 {
     for (TreeScope* scope = treeScope().parentTreeScope(); scope; scope = scope->parentTreeScope()) {
@@ -71,12 +89,13 @@ void ScopedStyleResolver::addFontFaceRules(const RuleSet& ruleSet)
     Document& document = treeScope().document();
     CSSFontSelector* cssFontSelector = document.styleEngine().fontSelector();
     const WillBeHeapVector<RawPtrWillBeMember<StyleRuleFontFace>> fontFaceRules = ruleSet.fontFaceRules();
+    if (!fontFaceRules.size())
+        return;
     for (auto& fontFaceRule : fontFaceRules) {
         if (RefPtrWillBeRawPtr<FontFace> fontFace = FontFace::create(&document, fontFaceRule))
             cssFontSelector->fontFaceCache()->add(cssFontSelector, fontFaceRule, fontFace);
     }
-    if (fontFaceRules.size())
-        document.styleResolver()->invalidateMatchedPropertiesCache();
+    document.styleResolver()->invalidateMatchedPropertiesCache();
 }
 
 void ScopedStyleResolver::appendCSSStyleSheet(CSSStyleSheet& cssSheet, const MediaQueryEvaluator& medium)