Implement ServiceWorkerFetchDispatcher::MaybeStartNavigationPreload().

content/browser/service_worker/service_worker_provider_host.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/service_worker/service_worker_provider_host.h"
 
 #include <utility>
 
 #include "base/guid.h"
 #include "base/stl_util.h"
@@ skipping 323 matching lines @@
     RequestContextFrameType frame_type,
     base::WeakPtr<storage::BlobStorageContext> blob_storage_context,
     scoped_refptr<ResourceRequestBodyImpl> body) {
   if (IsHostToRunningServiceWorker()) {
     return std::unique_ptr<ServiceWorkerRequestHandler>(
         new ServiceWorkerContextRequestHandler(
             context_, AsWeakPtr(), blob_storage_context, resource_type));
   }
   if (ServiceWorkerUtils::IsMainResourceType(resource_type) ||
       controlling_version()) {
+    // |dispatcher_host_| may be null in some unittests.
     return std::unique_ptr<ServiceWorkerRequestHandler>(
         new ServiceWorkerControlleeRequestHandler(
             context_, AsWeakPtr(), blob_storage_context, request_mode,
             credentials_mode, redirect_mode, resource_type,
-            request_context_type, frame_type, body));
+            request_context_type, frame_type, body,
+            dispatcher_host_ ? dispatcher_host_->url_loader_factory_callback()
+                             : ServiceWorkerControlleeRequestHandler::
+                                   URLLoaderFactoryCallback()));
   }
   return std::unique_ptr<ServiceWorkerRequestHandler>();
 }
 
 ServiceWorkerObjectInfo
 ServiceWorkerProviderHost::GetOrCreateServiceWorkerHandle(
     ServiceWorkerVersion* version) {
   DCHECK(dispatcher_host_);
   if (!context_ || !version)
     return ServiceWorkerObjectInfo();
@@ skipping 315 matching lines @@
       Send(new ServiceWorkerMsg_SetControllerServiceWorker(
           render_thread_id_, provider_id(),
           GetOrCreateServiceWorkerHandle(
               associated_registration_->active_version()),
           false /* shouldNotifyControllerChange */));
     }
   }
 }
 
 }  // namespace content