Delay bookmarks load while the profile is loading.

chrome/browser/profiles/startup_task_runner_service.h

+// 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.
+
+#ifndef CHROME_BROWSER_PROFILES_STARTUP_TASK_RUNNER_SERVICE_H_
+#define CHROME_BROWSER_PROFILES_STARTUP_TASK_RUNNER_SERVICE_H_
+
+#include "base/deferred_sequenced_task_runner.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/profiles/profile_keyed_service.h"
+
+class Profile;
+class ProfileDownloader;
+
+// This service manages the startup task runners.
+class StartupTaskRunnerService : public ProfileKeyedService {

[Jeffrey Yasskin, 2013/04/03 16:25:35]

There might be a simpler interface here. What if, instead of returning a literal
TaskRunner to post tasks on, you instead had a PostStartupTask method on this
class, which took both the TaskRunner to post to, and the arguments that
PostTask would normally take? (This class would then be a more metaphorical
TaskRunner.) Then the bookmarks service could specify the IOTaskRunner, and
other startup tasks could specify the appropriate task runners for themselves,
without having to store long-lived objects here or centralize the knowledge of
which TaskRunner is appropriate for each service.

[Jeffrey Yasskin, 2013/04/04 15:26:48]

DelayedTaskQueue at
https://code.google.com/p/chromium/codesearch/#chromium/src/chrome/browser/ex...
might argue against my point, or it might not because it's significantly simpler
than the DeferredSequencedTaskRunner.

[msarda, 2013/04/08 17:37:18]

I prefer the current interface as it avoids changing the other services
(bookmarks in my case).

[Jeffrey Yasskin, 2013/04/08 19:58:30]

Sure.

+ public:
+  explicit StartupTaskRunnerService(Profile* profile);
+  virtual ~StartupTaskRunnerService();
+
+  // Returns sequenced task runner where all bookmarks I/O operations are
+  // performed.
+  scoped_refptr<base::DeferredSequencedTaskRunner> GetBookmarkTaskRunner();

[Jeffrey Yasskin, 2013/04/03 16:25:35]

Please include a comment about why different services need separate startup task
runners, so that a future maintainer doesn't incorrectly simplify it down to a
single runner.

[msarda, 2013/04/08 17:37:18]

Done.

+
+  // Starts the task runners that are deferred during start-up.
+  void StartDeferredTaskRunners();
+
+ private:
+  Profile* profile_;
+  scoped_refptr<base::DeferredSequencedTaskRunner> bookmark_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(StartupTaskRunnerService);
+};
+
+#endif  // CHROME_BROWSER_PROFILES_STARTUP_TASK_RUNNER_SERVICE_H_