Protect EventListener from being deleted before it is passed into...

Protect EventListener from being deleted before it is passed into InspectorInstrumentation::didRemoveEventListener

BUG=358467

Review URL: https://codereview.chromium.org/220693002

git-svn-id: svn://svn.chromium.org/blink/trunk@170543 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/events/EventTarget.cpp

@@ -102,6 +102,7 @@ bool EventTarget::removeEventListener(const AtomicString& eventType, EventListen
 
     size_t indexOfRemovedListener;
 
+    RefPtr<EventListener> protect(listener);
     if (!d->eventListenerMap.remove(eventType, listener, useCapture, indexOfRemovedListener))
         return false;
     InspectorInstrumentation::didRemoveEventListener(this, eventType, listener, useCapture);