Reland of [Background Sync] Allow sync manager access from uncontrolled clients

content/child/background_sync/background_sync_provider_thread_proxy.cc

Index: content/child/background_sync/background_sync_provider_thread_proxy.cc
diff --git a/content/child/background_sync/background_sync_provider_thread_proxy.cc b/content/child/background_sync/background_sync_provider_thread_proxy.cc
index a5ecf2f8b9513ee02e9a6e7f65f90b40cd385c25..af0e78656d7b27081f43ca735abb1d622ea6822c 100644
--- a/content/child/background_sync/background_sync_provider_thread_proxy.cc
+++ b/content/child/background_sync/background_sync_provider_thread_proxy.cc
@@ -101,6 +101,7 @@ BackgroundSyncProviderThreadProxy::GetThreadInstance(
 void BackgroundSyncProviderThreadProxy::registerBackgroundSync(
     const blink::WebSyncRegistration* options,
     blink::WebServiceWorkerRegistration* service_worker_registration,
+    bool requested_from_service_worker,
     blink::WebSyncRegistrationCallbacks* callbacks) {
   DCHECK(options);
   DCHECK(service_worker_registration);
@@ -109,7 +110,7 @@ void BackgroundSyncProviderThreadProxy::registerBackgroundSync(
       FROM_HERE,
       base::Bind(&BackgroundSyncProvider::registerBackgroundSync,
                  base::Unretained(sync_provider_), options,
-                 service_worker_registration,
+                 service_worker_registration, requested_from_service_worker,
                  new CallbackThreadAdapter<blink::WebSyncRegistrationCallbacks>(
                      make_scoped_ptr(callbacks),
                      WorkerTaskRunner::Instance()->CurrentWorkerId())));