Run the later parts of startup as UI thread tasks

content/browser/startup_task_runner.cc

+// Copyright (c) 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/browser/startup_task_runner.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/message_loop/message_loop.h"
+
+namespace content {
+
+StartupTaskRunner::StartupTaskRunner(
+    bool browser_may_start_asynchronously,
+    void (*const startup_complete_callback)(int result),
+    scoped_refptr<base::SingleThreadTaskRunner> proxy)
+    : asynchronous_startup_(browser_may_start_asynchronously),
+      startup_complete_callback_(startup_complete_callback),
+      proxy_(proxy) {}
+
+void StartupTaskRunner::AddTask(StartupTask& callback) {
+  task_list_.push_back(callback);
+}
+
+void StartupTaskRunner::StartRunningTasks() {
+  DCHECK(proxy_);
+  int result = 0;
+  if (asynchronous_startup_ && !task_list_.empty()) {
+    const base::Closure next_task =
+        base::Bind(&StartupTaskRunner::WrappedTask, this);
+    proxy_->PostNonNestableTask(FROM_HERE, next_task);
+  } else {
+    for (std::list<StartupTask>::iterator it = task_list_.begin();
+         it != task_list_.end();
+         it++) {
+      result = it->Run();
+      if (result > 0) {
+        break;
+      }
+    }
+    startup_complete_callback_(result);
+  }
+}
+
+void StartupTaskRunner::WrappedTask() {
+  // Run the current task
+  int result = task_list_.front().Run();
+  task_list_.pop_front();
+  if (result > 0 || task_list_.empty()) {
+    startup_complete_callback_(result);
+  } else {
+    // Queue the next task
+    const base::Closure next_task =
+        base::Bind(&StartupTaskRunner::WrappedTask, this);
+    proxy_->PostNonNestableTask(FROM_HERE, next_task);
+  }
+}
+
+StartupTaskRunner::~StartupTaskRunner() {}
+
+}  // namespace content