PurgeMemory.

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

Index: third_party/WebKit/Source/core/css/StyleSheetContents.cpp
diff --git a/third_party/WebKit/Source/core/css/StyleSheetContents.cpp b/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
index fc39002b67f4fddd0c88cdff4f051e99829a50e8..e1c58e44821d9069e427fbf373e6c3f5f5494cbd 100644
--- a/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
+++ b/third_party/WebKit/Source/core/css/StyleSheetContents.cpp
@@ -662,6 +662,18 @@ void StyleSheetContents::findFontFaceRules(WillBeHeapVector<RawPtrWillBeMember<c
     findFontFaceRulesFromRules(childRules(), fontFaceRules);
 }
 
+void StyleSheetContents::purgeMemory()
+{
+    for (unsigned i = 0; i < m_importRules.size(); ++i) {
+        if (!m_importRules[i]->styleSheet())
+            continue;
+        m_importRules[i]->styleSheet()->purgeMemory();
+    }
+    for (WillBeHeapVector<RefPtrWillBeMember<StyleRuleBase>>::iterator it = m_childRules.begin(); it != m_childRules.end(); ++it)
+        (*it)->purgeMemory();
+    clearRuleSet();
+}
+
 DEFINE_TRACE(StyleSheetContents)
 {
 #if ENABLE(OILPAN)