EventSourceParserTest: fix invalid cast in GC finalizer.

third_party/WebKit/Source/core/page/EventSourceParserTest.cpp

Index: third_party/WebKit/Source/core/page/EventSourceParserTest.cpp
diff --git a/third_party/WebKit/Source/core/page/EventSourceParserTest.cpp b/third_party/WebKit/Source/core/page/EventSourceParserTest.cpp
index 800b15b6a471c8478f0ede35fded409d5674d9a9..d9db5532c5b6fb8fad0a355fa5face54def5ace9 100644
--- a/third_party/WebKit/Source/core/page/EventSourceParserTest.cpp
+++ b/third_party/WebKit/Source/core/page/EventSourceParserTest.cpp
@@ -59,7 +59,7 @@ private:
     Vector<EventOrReconnectionTimeSetting> m_events;
 };
 
-class StoppingClient : public GarbageCollectedFinalized<Client>, public EventSourceParser::Client {
+class StoppingClient : public GarbageCollectedFinalized<StoppingClient>, public EventSourceParser::Client {
     USING_GARBAGE_COLLECTED_MIXIN(StoppingClient);
 public:
     ~StoppingClient() override {}