Oilpan: dispose ServiceWorker (and registration) objects earlier.

Source/modules/serviceworkers/ServiceWorkerRegistration.cpp

Index: Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
diff --git a/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp b/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
index ba7061c3247cf0dc2dfcb425fca63af985c43a52..2771047dc03fc86c4bdd0ef9c6db7d96b6de1af3 100644
--- a/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
+++ b/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
@@ -145,6 +145,7 @@ ServiceWorkerRegistration::ServiceWorkerRegistration(ExecutionContext* execution
     , m_stopped(false)
 {
     ASSERT(m_outerRegistration);
+    ThreadState::current()->registerPreFinalizer(*this);
 
     if (!executionContext)
         return;
@@ -153,6 +154,17 @@ ServiceWorkerRegistration::ServiceWorkerRegistration(ExecutionContext* execution
     m_outerRegistration->setProxy(this);
 }
 
+ServiceWorkerRegistration::~ServiceWorkerRegistration()
+{
+    ASSERT(!m_outerRegistration);
+}
+
+void ServiceWorkerRegistration::dispose()
+{
+    // See ServiceWorker::dispose() comment why this explicit dispose() action is needed.
+    m_outerRegistration.clear();
+}
+
 void ServiceWorkerRegistration::trace(Visitor* visitor)
 {
     visitor->trace(m_installing);