Let IPC::SyncMessageFilter take advantage of thread-safe Send.

content/test/test_thread_safe_sender.cc

+// 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/test/test_thread_safe_sender.h"
+
+#include "base/synchronization/waitable_event.h"
+#include "base/threading/thread.h"
+#include "ipc/ipc_sync_channel.h"
+
+namespace content {
+
+namespace {
+
+class FakeIPCListener : public IPC::Listener {
+ public:
+  FakeIPCListener() {}
+  ~FakeIPCListener() override {}
+  bool OnMessageReceived(const IPC::Message& message) override { return false; }
+};
+
+}  // namespace
+
+// static
+scoped_refptr<ThreadSafeSender> TestThreadSafeSender::Create(
+    const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner) {
+  scoped_ptr<base::Thread> io_thread(
+      new base::Thread("TestThreadSafeSender IO"));
+  io_thread->Start();
+
+  scoped_ptr<base::WaitableEvent> shutdown_event(
+      new base::WaitableEvent(true /* manual_reset */,
+                              false /* initially_signaled */));
+  scoped_ptr<IPC::SyncChannel> sync_channel = IPC::SyncChannel::Create(
+      nullptr, io_thread->task_runner(), shutdown_event.get());
+  return new TestThreadSafeSender(main_task_runner, io_thread.Pass(),
+      shutdown_event.Pass(), sync_channel.Pass());
+}
+
+TestThreadSafeSender::TestThreadSafeSender(
+    const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
+    scoped_ptr<base::Thread> io_thread,
+    scoped_ptr<base::WaitableEvent> shutdown_event,
+    scoped_ptr<IPC::SyncChannel> sync_channel)
+    : ThreadSafeSender(main_task_runner,
+                       sync_channel->AddNewSyncMessageFilter()),
+      io_thread_(io_thread.Pass()),
+      shutdown_event_(shutdown_event.Pass()),
+      sync_channel_(sync_channel.Pass()) {
+}
+
+TestThreadSafeSender::~TestThreadSafeSender() {
+}
+
+}  // namespace content