Couple V8AbstractEventListener's lifetime to the V8 listeners lifetime

third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp b/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
index a8c1c700380a0fd7413c5298a9c25f9b923ce0f2..524680efb52f1c501fc519072797b339a1023c76 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8AbstractEventListener.cpp
@@ -48,19 +48,17 @@ V8AbstractEventListener::V8AbstractEventListener(bool isAttribute, DOMWrapperWor
     , m_isAttribute(isAttribute)
     , m_world(world)
     , m_isolate(isolate)
+    , m_workerGlobalScope(nullptr)
 {
     if (isMainThread())
         InstanceCounters::incrementCounter(InstanceCounters::JSEventListenerCounter);
+    else
+        m_workerGlobalScope = toWorkerGlobalScope(currentExecutionContext(isolate));
 }
 
 V8AbstractEventListener::~V8AbstractEventListener()
 {
-    if (!m_listener.isEmpty()) {
-        v8::HandleScope scope(isolate());
-        // We can't use a ScriptState::Scope here as the per-context data might already be gone at this point.
-        v8::Context::Scope contextScope(m_scriptStateForListener->context());
-        V8EventListenerList::clearWrapper(m_listener.newLocal(isolate()), m_isAttribute, m_scriptStateForListener.get());
-    }
+    ASSERT(m_listener.isEmpty());
     if (isMainThread())
         InstanceCounters::decrementCounter(InstanceCounters::JSEventListenerCounter);
 }
@@ -102,11 +100,21 @@ void V8AbstractEventListener::handleEvent(ScriptState* scriptState, Event* event
     invokeEventHandler(scriptState, event, v8::Local<v8::Value>::New(isolate(), jsEvent));
 }
 
-void V8AbstractEventListener::setListenerObject(v8::Local<v8::Object> listener, ScriptState* scriptState)
+void V8AbstractEventListener::setListenerObject(v8::Local<v8::Object> listener)
 {
+    ASSERT(m_listener.isEmpty());
+    // Balanced in secondWeakCallback xor clearListenerObject.
+    if (m_workerGlobalScope) {
+        m_workerGlobalScope->registerEventListener(this);
+    } else {
+#if ENABLE(OILPAN)
+        m_keepAlive = this;
+#else
+        ref();
+#endif
+    }
     m_listener.set(isolate(), listener);
     m_listener.setWeak(this, &setWeakCallback);
-    m_scriptStateForListener = scriptState;
 }
 
 void V8AbstractEventListener::invokeEventHandler(ScriptState* scriptState, Event* event, v8::Local<v8::Value> jsEvent)
@@ -184,10 +192,47 @@ bool V8AbstractEventListener::belongsToTheCurrentWorld() const
     return ScriptState::hasCurrentScriptState(isolate()) && &world() == &DOMWrapperWorld::current(isolate());
 }
 
-void V8AbstractEventListener::setWeakCallback(const v8::WeakCallbackInfo<V8AbstractEventListener> &data)
+void V8AbstractEventListener::clearListenerObject()
+{
+    if (!hasExistingListenerObject())
+        return;
+    m_listener.clear();
+    if (m_workerGlobalScope) {
+        m_workerGlobalScope->deregisterEventListener(this);
+    } else {
+#if ENABLE(OILPAN)
+        m_keepAlive.clear();
+#else
+        deref();
+#endif
+    }
+}
+
+void V8AbstractEventListener::setWeakCallback(const v8::WeakCallbackInfo<V8AbstractEventListener>& data)
 {
     data.GetParameter()->m_listener.clear();
-    data.GetParameter()->m_scriptStateForListener.clear();
+    data.SetSecondPassCallback(secondWeakCallback);
+}
+
+void V8AbstractEventListener::secondWeakCallback(const v8::WeakCallbackInfo<V8AbstractEventListener>& data)
+{
+    if (data.GetParameter()->m_workerGlobalScope) {
+        data.GetParameter()->m_workerGlobalScope->deregisterEventListener(data.GetParameter());
+    } else {
+#if ENABLE(OILPAN)
+        data.GetParameter()->m_keepAlive.clear();
+#else
+        data.GetParameter()->deref();
+#endif
+    }
+}
+
+DEFINE_TRACE(V8AbstractEventListener)
+{
+#if ENABLE(OILPAN)
+    visitor->trace(m_workerGlobalScope);
+#endif
+    EventListener::trace(visitor);
 }
 
 } // namespace blink