Implement a poor man's PostAfterStartupTask() function.

content/browser/after_startup_task_poster_impl.h

Index: content/browser/after_startup_task_poster_impl.h
diff --git a/content/browser/after_startup_task_poster_impl.h b/content/browser/after_startup_task_poster_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..339e559307a8a101fb5a8f0c5a5a83bb3397feeb
--- /dev/null
+++ b/content/browser/after_startup_task_poster_impl.h
@@ -0,0 +1,32 @@
+// Copyright (c) 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.
+
+#ifndef CONTENT_BROWSER_AFTER_STARTUP_TASK_POSTER_IMPL_H_
+#define CONTENT_BROWSER_AFTER_STARTUP_TASK_POSTER_IMPL_H_
+
+#include "content/public/browser/after_startup_task_poster.h"
+
+namespace content {
+
+class DefaultAfterStartupTaskPoster : public AfterStartupTaskPoster {
+ public:
+  void PostAfterStartup(
+      const tracked_objects::Location& from_here,
+      const scoped_refptr<base::TaskRunner>& task_runner,
+      const base::Closure& task) override;
+
+  void PostAfterStartupAndReply(
+      const tracked_objects::Location& from_here,
+      const scoped_refptr<base::TaskRunner>& task_runner,
+      const base::Closure& task,
+      const base::Closure& reply) override;
+};
+
+
+AfterStartupTaskPoster& GetAfterStartupTaskPoster();
+void SetAfterStartupTaskPoster(AfterStartupTaskPoster* task_poster);
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_AFTER_STARTUP_TASK_POSTER_IMPL_H_