Oilpan: promptly dispose style resolvers upon clearing.

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

Index: third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp b/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
index dd1ec1e8d8c81e2fb8b27cf5a7c3c0f4fc475fc0..a6610a0272c12f7eff39a30335f7c19bd5466f1b 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
@@ -163,6 +163,27 @@ StyleResolver::~StyleResolver()
 {
 }
 
+#if ENABLE(OILPAN)
+void StyleResolver::dispose()
+{
+    m_features.clear();
+    if (m_siblingRuleSet) {
+        m_siblingRuleSet->dispose();
+        m_siblingRuleSet.clear();
+    }
+    if (m_uncommonAttributeRuleSet) {
+        m_uncommonAttributeRuleSet->dispose();
+        m_uncommonAttributeRuleSet.clear();
+    }
+    m_styleSharingLists.clear();
+    if (m_watchedSelectorsRules) {
+        m_watchedSelectorsRules->dispose();
+        m_watchedSelectorsRules.clear();
+    }
+    m_pendingStyleSheets.clear();
+}
+#endif
+
 void StyleResolver::initWatchedSelectorRules()
 {
     CSSSelectorWatch* watch = CSSSelectorWatch::fromIfExists(*m_document);
@@ -1461,8 +1482,8 @@ void StyleResolver::computeFont(ComputedStyle* style, const StylePropertySet& pr
 
 void StyleResolver::addMediaQueryResults(const MediaQueryResultList& list)
 {
-    for (size_t i = 0; i < list.size(); ++i)
-        m_viewportDependentMediaQueryResults.append(list[i]);
+    if (list.size())
+        m_viewportDependentMediaQueryResults.appendVector(list);
 }
 
 bool StyleResolver::mediaQueryAffectedByViewportChange() const