ServiceWorker: Introduce SWMessageSender in order to mock IPC messaging

content/child/service_worker/service_worker_message_sender.cc

Index: content/child/service_worker/service_worker_message_sender.cc
diff --git a/content/child/service_worker/service_worker_message_sender.cc b/content/child/service_worker/service_worker_message_sender.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4602ff5c105ea24f453accdff4b8353e96daef60
--- /dev/null
+++ b/content/child/service_worker/service_worker_message_sender.cc
@@ -0,0 +1,23 @@
+// Copyright 2015 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/child/service_worker/service_worker_message_sender.h"
+
+#include "content/child/thread_safe_sender.h"
+
+namespace content {
+
+ServiceWorkerMessageSender::ServiceWorkerMessageSender(
+    ThreadSafeSender* thread_safe_sender)
+    : thread_safe_sender_(thread_safe_sender) {
+}
+
+bool ServiceWorkerMessageSender::Send(IPC::Message* message) {
+  return thread_safe_sender_->Send(message);
+}
+
+ServiceWorkerMessageSender::~ServiceWorkerMessageSender() {
+}
+
+}  // namespace content