Prepare DedicatedWorker for per thread heap

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

Index: third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerThread.cpp
diff --git a/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerThread.cpp b/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerThread.cpp
index a13c269296a2a960a8896ae32617ae04fa5e8d53..05c80323c80689931e33515d6ad3c41fcc389bc1 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerThread.cpp
+++ b/third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerThread.cpp
@@ -45,7 +45,7 @@ std::unique_ptr<ServiceWorkerThread> ServiceWorkerThread::create(PassRefPtr<Work
 
 ServiceWorkerThread::ServiceWorkerThread(PassRefPtr<WorkerLoaderProxy> workerLoaderProxy, WorkerReportingProxy& workerReportingProxy)
     : WorkerThread(std::move(workerLoaderProxy), workerReportingProxy)
-    , m_workerBackingThread(WorkerBackingThread::create("ServiceWorker Thread"))
+    , m_workerBackingThread(WorkerBackingThread::create("ServiceWorker Thread", BlinkGC::MainThreadHeapMode))
 {
 }