[Background Sync] Add sync registration details to onsync event

public/web/WebServiceWorkerContextProxy.h

Index: public/web/WebServiceWorkerContextProxy.h
diff --git a/public/web/WebServiceWorkerContextProxy.h b/public/web/WebServiceWorkerContextProxy.h
index ec71310cedf5532c6a87e84cbb6459c4626d0c09..989aebf37154d7243f52586e6225fdf7a22337d8 100644
--- a/public/web/WebServiceWorkerContextProxy.h
+++ b/public/web/WebServiceWorkerContextProxy.h
@@ -42,6 +42,7 @@ struct WebNotificationData;
 class WebServiceWorkerRegistration;
 class WebServiceWorkerRequest;
 class WebString;
+struct WebSyncRegistration;
 
 // A proxy interface to talk to the worker's GlobalScope implementation.
 // All methods of this class must be called on the worker thread.
@@ -67,9 +68,12 @@ public:
 
     virtual void dispatchCrossOriginMessageEvent(const WebCrossOriginServiceWorkerClient&, const WebString& message, const WebMessagePortChannelArray&) = 0;
 
-    // Once the ServiceWorker has finished handling the sync event
+    // Once the ServiceWorker has finished handling the sync event,
     // didHandleSyncEvent is called on the context client.
+    // FIXME: Remove the single-parameter version once all call sites have been
+    // updated.
     virtual void dispatchSyncEvent(int syncEventID) = 0;
+    virtual void dispatchSyncEvent(int syncEventID, const WebSyncRegistration&) = 0;
 
     virtual void addStashedMessagePorts(const WebMessagePortChannelArray& channels, const WebVector<WebString>& channelNames) = 0;
 };