Add IPC stubs between browser and ServiceWorker's worker context in the child process

content/renderer/service_worker/service_worker_context_message_filter.cc

Index: content/renderer/service_worker/service_worker_context_message_filter.cc
diff --git a/content/renderer/service_worker/service_worker_context_message_filter.cc b/content/renderer/service_worker/service_worker_context_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..26e83e881b79e40bc3e04346fc1acb824ed52ed0
--- /dev/null
+++ b/content/renderer/service_worker/service_worker_context_message_filter.cc
@@ -0,0 +1,48 @@
+// 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/renderer/service_worker/service_worker_context_message_filter.h"
+
+#include "base/message_loop/message_loop_proxy.h"
+#include "content/child/child_thread.h"
+#include "content/child/thread_safe_sender.h"
+#include "content/child/worker_thread_task_runner.h"
+#include "content/renderer/service_worker/service_worker_context_client.h"
+#include "ipc/ipc_message_macros.h"
+
+namespace content {
+
+ServiceWorkerContextMessageFilter::ServiceWorkerContextMessageFilter()
+    : main_thread_loop_proxy_(base::MessageLoopProxy::current()),
+      thread_safe_sender_(ChildThread::current()->thread_safe_sender()) {}
+
+ServiceWorkerContextMessageFilter::~ServiceWorkerContextMessageFilter() {}
+
+base::TaskRunner*
+ServiceWorkerContextMessageFilter::OverrideTaskRunnerForMessage(
+    const IPC::Message& msg) {
+  if (IPC_MESSAGE_CLASS(msg) != ServiceWorkerContextMsgStart)
+    return NULL;
+  int ipc_thread_id = 0;
+  const bool success = PickleIterator(msg).ReadInt(&ipc_thread_id);
+  DCHECK(success);
+  if (!ipc_thread_id)
+    return main_thread_loop_proxy_.get();
+  return new WorkerThreadTaskRunner(ipc_thread_id);
+}
+
+bool ServiceWorkerContextMessageFilter::OnMessageReceived(
+    const IPC::Message& msg) {
+  if (IPC_MESSAGE_CLASS(msg) != ServiceWorkerContextMsgStart)
+    return false;
+  ServiceWorkerContextClient* client =
+      ServiceWorkerContextClient::ThreadSpecificInstance();
+  if (!client) {
+    LOG(ERROR) << "Stray message is sent to nonexistent worker";
+    return true;
+  }
+  return client->OnMessageReceived(msg);
+}
+
+}  // namespace content