Stop passing const-reference of SWRegistration in all GetRegistrationsCallbacks.

content/browser/service_worker/service_worker_context_unittest.cc

Index: content/browser/service_worker/service_worker_context_unittest.cc
diff --git a/content/browser/service_worker/service_worker_context_unittest.cc b/content/browser/service_worker/service_worker_context_unittest.cc
index 05409c833aaba021039bacbda59de0b798a4dcdf..fdfee7bc65eacd3056be329b829b5c791e1a9ef0 100644
--- a/content/browser/service_worker/service_worker_context_unittest.cc
+++ b/content/browser/service_worker/service_worker_context_unittest.cc
@@ -59,7 +59,7 @@ void ExpectRegisteredWorkers(
     bool expect_waiting,
     bool expect_active,
     ServiceWorkerStatusCode status,
-    const scoped_refptr<ServiceWorkerRegistration>& registration) {
+    scoped_refptr<ServiceWorkerRegistration> registration) {
   ASSERT_EQ(expect_status, status);
   if (status != SERVICE_WORKER_OK) {
     EXPECT_FALSE(registration.get());