Implement a poor man's PostAfterStartupTask() function.

content/public/browser/browser_thread.h

 // Copyright (c) 2012 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_PUBLIC_BROWSER_BROWSER_THREAD_H_
 #define CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 166 matching lines @@
                                    const base::Closure& task);
   static bool PostBlockingPoolTaskAndReply(
       const tracked_objects::Location& from_here,
       const base::Closure& task,
       const base::Closure& reply);
   static bool PostBlockingPoolSequencedTask(
       const std::string& sequence_token_name,
       const tracked_objects::Location& from_here,
       const base::Closure& task);
 
+  // For use with scheduling non-critical tasks for exeuction after startup.

[jam, 2015/03/10 23:04:34]

nit: spelling

+  // The order or execution of tasks posted here is unspecified even when
+  // posting to a SequencedTaskRunner.
+  // Note: the embedder must override ContentBrowserClient.PostAfterStartupTask
+  // to provide this function, otherwise the default behavior is to post the
+  // task immediately.

[jam, 2015/03/10 23:04:34]

nit: i think the "Note" part is confusing. it starts by making it seem like if
the CBC method isn't implemented, this method doesn't work. then it says it has
default behavior.

[michaeln, 2015/03/20 00:21:28]

Done.

// Note: see related ContentBrowserClient.PostAfterStartupTask.

+  static void PostAfterStartupTask(
+      const tracked_objects::Location& from_here,
+      const scoped_refptr<base::TaskRunner>& task_runner,
+      const base::Closure& task);
+
   // Returns the thread pool used for blocking file I/O. Use this object to
   // perform random blocking operations such as file writes or querying the
   // Windows registry.
   static base::SequencedWorkerPool* GetBlockingPool() WARN_UNUSED_RESULT;
 
   // Callable on any thread.  Returns whether the given well-known thread is
   // initialized.
   static bool IsThreadInitialized(ID identifier) WARN_UNUSED_RESULT;
 
   // Callable on any thread.  Returns whether you're currently on a particular
@@ skipping 90 matching lines @@
  private:
   friend class BrowserThreadImpl;
 
   BrowserThread() {}
   DISALLOW_COPY_AND_ASSIGN(BrowserThread);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_