1 files changed, 2 insertions, 1 deletions
diff --git a/chromium/third_party/WebKit/Source/core/css/CSSUnknownRule.h b/chromium/third_party/WebKit/Source/core/css/CSSUnknownRule.h
index 629aaead0d3..06d1be4283a 100644
--- a/chromium/third_party/WebKit/Source/core/css/CSSUnknownRule.h
+++ b/chromium/third_party/WebKit/Source/core/css/CSSUnknownRule.h
@@ -26,7 +26,7 @@
 
 namespace WebCore {
 
-class CSSUnknownRule : public CSSRule {
+class CSSUnknownRule FINAL : public CSSRule {
 public:
     CSSUnknownRule() : CSSRule(0) { }
     virtual ~CSSUnknownRule() { }
@@ -34,6 +34,7 @@ public:
     virtual CSSRule::Type type() const OVERRIDE { return UNKNOWN_RULE; }
     virtual String cssText() const OVERRIDE { return String(); }
     virtual void reattach(StyleRuleBase*) OVERRIDE { }
+    virtual void trace(Visitor* visitor) OVERRIDE { CSSRule::trace(visitor); }
 };
 
 } // namespace WebCore