Teach Background Fetch how to start a new fetch.

content/browser/background_fetch/background_fetch_service_impl.h

Index: content/browser/background_fetch/background_fetch_service_impl.h
diff --git a/content/browser/background_fetch/background_fetch_service_impl.h b/content/browser/background_fetch/background_fetch_service_impl.h
index de6299b8c5cc9ee7dd51b3371bd464b4d033d181..c9dd5bf82f0b52095764bb2471a307bc72e233a6 100644
--- a/content/browser/background_fetch/background_fetch_service_impl.h
+++ b/content/browser/background_fetch/background_fetch_service_impl.h
@@ -25,14 +25,12 @@ class ServiceWorkerContextWrapper;
 
 class BackgroundFetchServiceImpl : public blink::mojom::BackgroundFetchService {
  public:
-  BackgroundFetchServiceImpl(
-      scoped_refptr<BackgroundFetchContext> background_fetch_context,
-      scoped_refptr<ServiceWorkerContextWrapper> service_worker_context);
+  explicit BackgroundFetchServiceImpl(
+      scoped_refptr<BackgroundFetchContext> background_fetch_context);
   ~BackgroundFetchServiceImpl() override;
 
   static void Create(
       scoped_refptr<BackgroundFetchContext> background_fetch_context,
-      scoped_refptr<ServiceWorkerContextWrapper> service_worker_context,
       blink::mojom::BackgroundFetchServiceRequest request);
 
   // blink::mojom::BackgroundFetchService implementation.
@@ -60,7 +58,6 @@ class BackgroundFetchServiceImpl : public blink::mojom::BackgroundFetchService {
 
  private:
   scoped_refptr<BackgroundFetchContext> background_fetch_context_;
-  scoped_refptr<ServiceWorkerContextWrapper> service_worker_context_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundFetchServiceImpl);
 };