The blink half of the new ServiceWorker 'sync' event.

public/web/WebServiceWorkerContextProxy.h

Index: public/web/WebServiceWorkerContextProxy.h
diff --git a/public/web/WebServiceWorkerContextProxy.h b/public/web/WebServiceWorkerContextProxy.h
index 07278c096a2bde929777c501da601dda43e019cd..546773d7a514a250b4fb0dcb69fdcd164b028aaf 100644
--- a/public/web/WebServiceWorkerContextProxy.h
+++ b/public/web/WebServiceWorkerContextProxy.h
@@ -46,6 +46,10 @@ public:
     // FIXME: This needs to pass the fetch request info.
     virtual void dispatchFetchEvent(int fetchEventID) = 0;
 
+    // Once the ServiceWorker has finished handling the sync event
+    // didHandleSyncEvent is called on the context client.
+    virtual void dispatchSyncEvent(int syncEventID) = 0;
+
     virtual void resumeWorkerContext() { }
     virtual void attachDevTools() { }
     virtual void reattachDevTools(const WebString& savedState) { }