Add layout tests for hasPermission

Source/modules/push_messaging/PushManager.cpp

 // Copyright 2014 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 "config.h"
 #include "modules/push_messaging/PushManager.h"
 
 #include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
@@ skipping 54 matching lines @@
     ASSERT(client);
 
     // The currently implemented specification does not require a Service Worker to be present for the
     // hasPermission() call to work, but it will become a requirement soon.
     WebServiceWorkerProvider* serviceWorkerProvider = NavigatorServiceWorker::serviceWorker(document->domWindow()->navigator())->provider();
     if (!serviceWorkerProvider)
         return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "No Service Worker installed for this document."));
 
     RefPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
 
+    ScriptPromise promise = resolver->promise();
     client->getPermissionStatus(new PushPermissionCallback(resolver), serviceWorkerProvider);
-    return resolver->promise();
+    return promise;
 }
 
 } // namespace blink