Oilpan: Replace EAGERLY_FINALIZE in EventTarget's hierarchy with pre-finalizers

third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp

Index: third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
diff --git a/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp b/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
index f0490d96d5efd72e428b1c0e662cab5ca536fd0e..f0c3b253023879cff47d7d4eb4cf2a24fe7197c8 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
+++ b/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
@@ -106,6 +106,7 @@ ServiceWorkerRegistration::ServiceWorkerRegistration(ExecutionContext* execution
 {
     ASSERT(m_handle);
     ASSERT(!m_handle->registration()->proxy());
+    ThreadState::current()->registerPreFinalizer(this);
 
     if (!executionContext)
         return;
@@ -118,6 +119,13 @@ ServiceWorkerRegistration::~ServiceWorkerRegistration()
 {
 }
 
+void ServiceWorkerRegistration::dispose()
+{
+    // Promptly clears a raw reference from content/ to an on-heap object
+    // so that content/ doesn't access it in a lazy sweeping phase.
+    m_handle.clear();
+}
+
 DEFINE_TRACE(ServiceWorkerRegistration)
 {
     visitor->trace(m_installing);