Set up content in-process main threads via factory

content/utility/utility_main_thread.cc

+// 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/utility/utility_main_thread.h"
+
+#include "content/child/child_process.h"
+#include "content/utility/utility_thread_impl.h"
+
+namespace content {
+
+// We want to ensure there's only one utility thread running at a time, as there
+// are many globals used in the utility process.
+static base::LazyInstance<base::Lock> g_one_utility_thread_lock;
+
+UtilityMainThread::UtilityMainThread(const std::string& channel_id)
+    : Thread("Chrome_InProcUtilityThread"), channel_id_(channel_id) {
+}
+
+UtilityMainThread::~UtilityMainThread() {
+  Stop();
+}
+
+void UtilityMainThread::Init() {
+  // We need to return right away or else the main thread that started us will
+  // hang.
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(&UtilityMainThread::InitInternal, base::Unretained(this)));
+}
+
+void UtilityMainThread::CleanUp() {
+  child_process_.reset();
+
+  // See comment in RendererMainThread.
+  SetThreadWasQuitProperly(true);
+  g_one_utility_thread_lock.Get().Release();
+}
+
+void UtilityMainThread::InitInternal() {
+  g_one_utility_thread_lock.Get().Acquire();
+  child_process_.reset(new ChildProcess());
+  child_process_->set_main_thread(new UtilityThreadImpl(channel_id_));
+}
+
+base::Thread* CreateUtilityMainThread(const std::string& channel_id) {
+  return new UtilityMainThread(channel_id);
+}
+
+}  // namespace content