Delay bookmarks load while the profile is loading.

This CL adds a new DeferredSequencedtaskRunner that queues up tasks
until a first call to Start is issued. It creates such a task runner for the 
execution of bookmarks I/O operations. At profile creation, the bookmarks
task runner is stopped and its execution is started after the profile has
finished loading.

BUG=NONE

Review URL: https://chromiumcodereview.appspot.com/12952005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@194956 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 558 insertions, 13 deletions

diff --git a/base/base.gyp b/base/base.gyp
index 290961e..b026dcb 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -463,6 +463,7 @@
         'debug/trace_event_unittest.cc',
         'debug/trace_event_unittest.h',
         'debug/trace_event_win_unittest.cc',
+        'deferred_sequenced_task_runner_unittest.cc',
         'environment_unittest.cc',
         'file_util_unittest.cc',
         'file_version_info_unittest.cc',
diff --git a/base/base.gypi b/base/base.gypi
index f26c4c7..164aa23 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -137,6 +137,8 @@
           'debug/trace_event_impl.cc',
           'debug/trace_event_impl.h',
           'debug/trace_event_win.cc',
+          'deferred_sequenced_task_runner.cc',
+          'deferred_sequenced_task_runner.h',
           'environment.cc',
           'environment.h',
           'file_descriptor_posix.h',
diff --git a/base/deferred_sequenced_task_runner.cc b/base/deferred_sequenced_task_runner.cc
new file mode 100644
index 0000000..c96704c
--- /dev/null
+++ b/base/deferred_sequenced_task_runner.cc
@@ -0,0 +1,99 @@
+// 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 "base/deferred_sequenced_task_runner.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+
+namespace base {
+
+DeferredSequencedTaskRunner::DeferredTask::DeferredTask() {
+}
+
+DeferredSequencedTaskRunner::DeferredTask::~DeferredTask() {
+}
+
+DeferredSequencedTaskRunner::DeferredSequencedTaskRunner(
+    const scoped_refptr<SequencedTaskRunner>& target_task_runner)
+    : started_(false),
+      target_task_runner_(target_task_runner) {
+}
+
+DeferredSequencedTaskRunner::~DeferredSequencedTaskRunner() {
+}
+
+bool DeferredSequencedTaskRunner::PostDelayedTask(
+    const tracked_objects::Location& from_here,
+    const Closure& task,
+    TimeDelta delay) {
+  AutoLock lock(lock_);
+  if (started_) {
+    DCHECK(deferred_tasks_queue_.empty());
+    return target_task_runner_->PostDelayedTask(from_here, task, delay);
+  }
+
+  QueueDeferredTask(from_here, task, delay, false /* is_non_nestable */);
+  return true;
+}
+
+bool DeferredSequencedTaskRunner::RunsTasksOnCurrentThread() const {
+  return target_task_runner_->RunsTasksOnCurrentThread();
+}
+
+bool DeferredSequencedTaskRunner::PostNonNestableDelayedTask(
+    const tracked_objects::Location& from_here,
+    const Closure& task,
+    TimeDelta delay) {
+  AutoLock lock(lock_);
+  if (started_) {
+    DCHECK(deferred_tasks_queue_.empty());
+    return target_task_runner_->PostNonNestableDelayedTask(from_here,
+                                                           task,
+                                                           delay);
+  }
+  QueueDeferredTask(from_here, task, delay, true /* is_non_nestable */);
+  return true;
+}
+
+void DeferredSequencedTaskRunner::QueueDeferredTask(
+    const tracked_objects::Location& from_here,
+    const Closure& task,
+    TimeDelta delay,
+    bool is_non_nestable) {
+  DeferredTask deferred_task;
+  deferred_task.posted_from = from_here;
+  deferred_task.task = task;
+  deferred_task.delay = delay;
+  deferred_task.is_non_nestable = is_non_nestable;
+  deferred_tasks_queue_.push_back(deferred_task);
+}
+
+
+void DeferredSequencedTaskRunner::Start() {
+  AutoLock lock(lock_);
+  DCHECK(!started_);
+  started_ = true;
+  for (std::vector<DeferredTask>::iterator i = deferred_tasks_queue_.begin();
+      i != deferred_tasks_queue_.end();
+      ++i) {
+    const DeferredTask& task = *i;
+    if (task.is_non_nestable) {
+      target_task_runner_->PostNonNestableDelayedTask(task.posted_from,
+                                                      task.task,
+                                                      task.delay);
+    } else {
+      target_task_runner_->PostDelayedTask(task.posted_from,
+                                           task.task,
+                                           task.delay);
+    }
+    // Replace the i-th element in the |deferred_tasks_queue_| with an empty
+    // |DelayedTask| to ensure that |task| is destroyed before the next task
+    // is posted.
+    *i = DeferredTask();
+  }
+  deferred_tasks_queue_.clear();
+}
+
+}  // namespace base
diff --git a/base/deferred_sequenced_task_runner.h b/base/deferred_sequenced_task_runner.h
new file mode 100644
index 0000000..d1cdb43
--- /dev/null
+++ b/base/deferred_sequenced_task_runner.h
@@ -0,0 +1,79 @@
+// 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 BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
+#define BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
+
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "base/synchronization/lock.h"
+#include "base/time.h"
+#include "base/tracked_objects.h"
+
+namespace base {
+
+// A DeferredSequencedTaskRunner is a subclass of SequencedTaskRunner that
+// queues up all requests until the first call to Start() is issued.
+class BASE_EXPORT DeferredSequencedTaskRunner : public SequencedTaskRunner {
+ public:
+  explicit DeferredSequencedTaskRunner(
+      const scoped_refptr<SequencedTaskRunner>& target_runner);
+
+  // TaskRunner implementation
+  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                               const Closure& task,
+                               TimeDelta delay) OVERRIDE;
+  virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
+
+  // SequencedTaskRunner implementation
+  virtual bool PostNonNestableDelayedTask(
+      const tracked_objects::Location& from_here,
+      const Closure& task,
+      TimeDelta delay) OVERRIDE;
+
+  // Start the execution - posts all queued tasks to the target executor. The
+  // deferred tasks are posted with their initial delay, meaning that the task
+  // execution delay is actually measured from Start.
+  // Fails when called a second time.
+  void Start();
+
+ private:
+  struct DeferredTask  {
+    DeferredTask();
+    ~DeferredTask();
+
+    tracked_objects::Location posted_from;
+    Closure task;
+    // The delay this task was initially posted with.
+    TimeDelta delay;
+    bool is_non_nestable;
+  };
+
+  virtual ~DeferredSequencedTaskRunner();
+
+  // Creates a |Task| object and adds it to |deferred_tasks_queue_|.
+  void QueueDeferredTask(const tracked_objects::Location& from_here,
+                         const Closure& task,
+                         TimeDelta delay,
+                         bool is_non_nestable);
+
+  // // Protects |started_| and |deferred_tasks_queue_|.
+  mutable Lock lock_;
+
+  bool started_;
+  const scoped_refptr<SequencedTaskRunner> target_task_runner_;
+  std::vector<DeferredTask> deferred_tasks_queue_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeferredSequencedTaskRunner);
+};
+
+}  // namespace base
+
+#endif  // BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
diff --git a/base/deferred_sequenced_task_runner_unittest.cc b/base/deferred_sequenced_task_runner_unittest.cc
new file mode 100644
index 0000000..c033ba8
--- /dev/null
+++ b/base/deferred_sequenced_task_runner_unittest.cc
@@ -0,0 +1,184 @@
+// 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 "base/deferred_sequenced_task_runner.h"
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/memory/ref_counted.h"
+#include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
+#include "base/threading/non_thread_safe.h"
+#include "base/threading/thread.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class DeferredSequencedTaskRunnerTest : public testing::Test,
+                                        public base::NonThreadSafe {
+ public:
+  class ExecuteTaskOnDestructor :
+      public base::RefCounted<ExecuteTaskOnDestructor> {
+   public:
+    ExecuteTaskOnDestructor(
+        DeferredSequencedTaskRunnerTest* executor,
+        int task_id)
+        : executor_(executor),
+          task_id_(task_id) {
+    }
+  private:
+    friend class base::RefCounted<ExecuteTaskOnDestructor>;
+    virtual ~ExecuteTaskOnDestructor() {
+      executor_->ExecuteTask(task_id_);
+    }
+    DeferredSequencedTaskRunnerTest* executor_;
+    int task_id_;
+  };
+
+  void ExecuteTask(int task_id) {
+    base::AutoLock lock(lock_);
+    executed_task_ids_.push_back(task_id);
+  }
+
+  void PostExecuteTask(int task_id) {
+    runner_->PostTask(FROM_HERE,
+                      base::Bind(&DeferredSequencedTaskRunnerTest::ExecuteTask,
+                                 base::Unretained(this),
+                                 task_id));
+  }
+
+  void StartRunner() {
+    runner_->Start();
+  }
+
+  void DoNothing(ExecuteTaskOnDestructor* object) {
+  }
+
+ protected:
+  DeferredSequencedTaskRunnerTest() :
+      loop_(),
+      runner_(
+          new base::DeferredSequencedTaskRunner(loop_.message_loop_proxy())) {
+  }
+
+  MessageLoop loop_;
+  scoped_refptr<base::DeferredSequencedTaskRunner> runner_;
+  mutable base::Lock lock_;
+  std::vector<int> executed_task_ids_;
+};
+
+TEST_F(DeferredSequencedTaskRunnerTest, Stopped) {
+  PostExecuteTask(1);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre());
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, Start) {
+  StartRunner();
+  PostExecuteTask(1);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, StartWithMultipleElements) {
+  StartRunner();
+  for (int i = 1; i < 5; ++i)
+    PostExecuteTask(i);
+
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1, 2, 3, 4));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, DeferredStart) {
+  PostExecuteTask(1);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre());
+
+  StartRunner();
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1));
+
+  PostExecuteTask(2);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1, 2));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, DeferredStartWithMultipleElements) {
+  for (int i = 1; i < 5; ++i)
+    PostExecuteTask(i);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre());
+
+  StartRunner();
+  for (int i = 5; i < 9; ++i)
+    PostExecuteTask(i);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1, 2, 3, 4, 5, 6, 7, 8));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, DeferredStartWithMultipleThreads) {
+  {
+    base::Thread thread1("DeferredSequencedTaskRunnerTestThread1");
+    base::Thread thread2("DeferredSequencedTaskRunnerTestThread2");
+    thread1.Start();
+    thread2.Start();
+    for (int i = 0; i < 5; ++i) {
+      thread1.message_loop()->PostTask(
+          FROM_HERE,
+          base::Bind(&DeferredSequencedTaskRunnerTest::PostExecuteTask,
+                     base::Unretained(this),
+                     2 * i));
+      thread2.message_loop()->PostTask(
+          FROM_HERE,
+          base::Bind(&DeferredSequencedTaskRunnerTest::PostExecuteTask,
+                     base::Unretained(this),
+                     2 * i + 1));
+      if (i == 2) {
+        thread1.message_loop()->PostTask(
+            FROM_HERE,
+            base::Bind(&DeferredSequencedTaskRunnerTest::StartRunner,
+                       base::Unretained(this)));
+      }
+    }
+  }
+
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_,
+      testing::WhenSorted(testing::ElementsAre(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, ObjectDestructionOrder) {
+  {
+    base::Thread thread("DeferredSequencedTaskRunnerTestThread");
+    thread.Start();
+    runner_ =
+        new base::DeferredSequencedTaskRunner(thread.message_loop_proxy());
+    for (int i = 0; i < 5; ++i) {
+      {
+        // Use a block to ensure that no reference to |short_lived_object|
+        // is kept on the main thread after it is posted to |runner_|.
+        scoped_refptr<ExecuteTaskOnDestructor> short_lived_object =
+            new ExecuteTaskOnDestructor(this, 2 * i);
+        runner_->PostTask(
+            FROM_HERE,
+            base::Bind(&DeferredSequencedTaskRunnerTest::DoNothing,
+                       base::Unretained(this),
+                       short_lived_object));
+      }
+      // |short_lived_object| with id |2 * i| should be destroyed before the
+      // task |2 * i + 1| is executed.
+      PostExecuteTask(2 * i + 1);
+    }
+    StartRunner();
+  }
+
+  // All |short_lived_object| with id |2 * i| are destroyed before the task
+  // |2 * i + 1| is executed.
+  EXPECT_THAT(executed_task_ids_,
+              testing::ElementsAre(0, 1, 2, 3, 4, 5, 6, 7, 8, 9));
+}
+
+}  // namespace
diff --git a/chrome/browser/bookmarks/DEPS b/chrome/browser/bookmarks/DEPS
index 104e900..4c3d5ac 100644
--- a/chrome/browser/bookmarks/DEPS
+++ b/chrome/browser/bookmarks/DEPS
@@ -22,6 +22,8 @@ include_rules = [
   "!chrome/browser/profiles/profile_dependency_manager.h",
   "!chrome/browser/profiles/profile_keyed_service.h",
   "!chrome/browser/profiles/profile_keyed_service_factory.h",
+  "!chrome/browser/profiles/startup_task_runner_service.h",
+  "!chrome/browser/profiles/startup_task_runner_service_factory.h",
   # Do not add to the list of temporarily-allowed dependencies above,
   # and please do not introduce more #includes of these files.
 ]
diff --git a/chrome/browser/bookmarks/bookmark_model.cc b/chrome/browser/bookmarks/bookmark_model.cc
index 150afd4..d23f645 100644
--- a/chrome/browser/bookmarks/bookmark_model.cc
+++ b/chrome/browser/bookmarks/bookmark_model.cc
@@ -232,7 +232,8 @@ void BookmarkModel::Shutdown() {
   loaded_signal_.Signal();
 }
 
-void BookmarkModel::Load() {
+void BookmarkModel::Load(
+    const scoped_refptr<base::SequencedTaskRunner>& task_runner) {
   if (store_.get()) {
     // If the store is non-null, it means Load was already invoked. Load should
     // only be invoked once.
@@ -249,7 +250,7 @@ void BookmarkModel::Load() {
                  content::Source<Profile>(profile_));
 
   // Load the bookmarks. BookmarkStorage notifies us when done.
-  store_ = new BookmarkStorage(profile_, this, profile_->GetIOTaskRunner());
+  store_ = new BookmarkStorage(profile_, this, task_runner);
   store_->LoadBookmarks(CreateLoadDetails());
 }
 
diff --git a/chrome/browser/bookmarks/bookmark_model.h b/chrome/browser/bookmarks/bookmark_model.h
index 1d846d7..9853d38 100644
--- a/chrome/browser/bookmarks/bookmark_model.h
+++ b/chrome/browser/bookmarks/bookmark_model.h
@@ -33,6 +33,10 @@ class BookmarkModelObserver;
 class BookmarkStorage;
 class Profile;
 
+namespace base {
+class SequencedTaskRunner;
+}
+
 namespace bookmark_utils {
 struct TitleMatch;
 }
@@ -236,7 +240,8 @@ class BookmarkModel : public content::NotificationObserver,
 
   // Loads the bookmarks. This is called upon creation of the
   // BookmarkModel. You need not invoke this directly.
-  void Load();
+  // All load operations will be executed on |task_runner|.
+  void Load(const scoped_refptr<base::SequencedTaskRunner>& task_runner);
 
   // Returns true if the model finished loading.
   // This is virtual so it can be mocked.
diff --git a/chrome/browser/bookmarks/bookmark_model_factory.cc b/chrome/browser/bookmarks/bookmark_model_factory.cc
index 1f63b6d..73da8cb 100644
--- a/chrome/browser/bookmarks/bookmark_model_factory.cc
+++ b/chrome/browser/bookmarks/bookmark_model_factory.cc
@@ -4,11 +4,14 @@
 
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 
+#include "base/deferred_sequenced_task_runner.h"
 #include "base/memory/singleton.h"
 #include "base/values.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_dependency_manager.h"
+#include "chrome/browser/profiles/startup_task_runner_service.h"
+#include "chrome/browser/profiles/startup_task_runner_service_factory.h"
 #include "chrome/common/pref_names.h"
 #include "components/user_prefs/pref_registry_syncable.h"
 
@@ -38,7 +41,8 @@ BookmarkModelFactory::~BookmarkModelFactory() {}
 ProfileKeyedService* BookmarkModelFactory::BuildServiceInstanceFor(
     Profile* profile) const {
   BookmarkModel* bookmark_model = new BookmarkModel(profile);
-  bookmark_model->Load();
+  bookmark_model->Load(StartupTaskRunnerServiceFactory::GetForProfile(profile)->
+      GetBookmarkTaskRunner());
   return bookmark_model;
 }
 
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index e157d1f..ce4ff02 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -8,6 +8,7 @@
 
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/deferred_sequenced_task_runner.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/metrics/histogram.h"
@@ -25,6 +26,8 @@
 #include "chrome/browser/profiles/profile_destroyer.h"
 #include "chrome/browser/profiles/profile_info_cache.h"
 #include "chrome/browser/profiles/profile_metrics.h"
+#include "chrome/browser/profiles/startup_task_runner_service.h"
+#include "chrome/browser/profiles/startup_task_runner_service_factory.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "chrome/browser/ui/browser.h"
@@ -847,6 +850,9 @@ void ProfileManager::DoFinalInitForServices(Profile* profile,
   // initializing the managed flag if necessary).
   ManagedUserServiceFactory::GetForProfile(profile)->Init();
 #endif
+  // Start the deferred task runners once the profile is loaded.
+  StartupTaskRunnerServiceFactory::GetForProfile(profile)->
+      StartDeferredTaskRunners();
 }
 
 void ProfileManager::DoFinalInitLogging(Profile* profile) {
@@ -1173,12 +1179,17 @@ ProfileManagerWithoutInit::ProfileManagerWithoutInit(
 }
 
 void ProfileManager::RegisterTestingProfile(Profile* profile,
-                                            bool add_to_cache) {
+                                            bool add_to_cache,
+                                            bool start_deferred_task_runners) {
   RegisterProfile(profile, true);
   if (add_to_cache) {
     InitProfileUserPrefs(profile);
     AddProfileToCache(profile);
   }
+  if (start_deferred_task_runners) {
+    StartupTaskRunnerServiceFactory::GetForProfile(profile)->
+        StartDeferredTaskRunners();
+  }
 }
 
 void ProfileManager::RunCallbacks(const std::vector<CreateCallback>& callbacks,
diff --git a/chrome/browser/profiles/profile_manager.h b/chrome/browser/profiles/profile_manager.h
index a93d457..6cee37b8 100644
--- a/chrome/browser/profiles/profile_manager.h
+++ b/chrome/browser/profiles/profile_manager.h
@@ -211,10 +211,14 @@ class ProfileManager : public base::NonThreadSafe,
   // Autoloads profiles if they are running background apps.
   void AutoloadProfiles();
 
-  // Register and add testing profile to the ProfileManager. Use ONLY in tests.
+  // Registers and adds testing profile to the ProfileManager.
   // This allows the creation of Profiles outside of the standard creation path
-  // for testing. If |addToCache|, add to ProfileInfoCache as well.
-  void RegisterTestingProfile(Profile* profile, bool addToCache);
+  // for testing. If |addToCache|, adds to ProfileInfoCache as well.
+  // If |start_deferred_task_runners|, starts the deferred task runners.
+  // Use ONLY in tests.
+  void RegisterTestingProfile(Profile* profile,
+                              bool addToCache,
+                              bool start_deferred_task_runners);
 
   const base::FilePath& user_data_dir() const { return user_data_dir_; }
 
diff --git a/chrome/browser/profiles/startup_task_runner_service.cc b/chrome/browser/profiles/startup_task_runner_service.cc
new file mode 100644
index 0000000..60407e1
--- /dev/null
+++ b/chrome/browser/profiles/startup_task_runner_service.cc
@@ -0,0 +1,30 @@
+// 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 "chrome/browser/profiles/startup_task_runner_service.h"
+
+#include "base/deferred_sequenced_task_runner.h"
+#include "base/logging.h"
+#include "chrome/browser/profiles/profile.h"
+
+StartupTaskRunnerService::StartupTaskRunnerService(Profile* profile)
+    : profile_(profile) {
+}
+
+StartupTaskRunnerService::~StartupTaskRunnerService() {
+}
+
+scoped_refptr<base::DeferredSequencedTaskRunner>
+    StartupTaskRunnerService::GetBookmarkTaskRunner() {
+  DCHECK(CalledOnValidThread());
+  if (!bookmark_task_runner_) {
+    bookmark_task_runner_ =
+        new base::DeferredSequencedTaskRunner(profile_->GetIOTaskRunner());
+  }
+  return bookmark_task_runner_;
+}
+
+void StartupTaskRunnerService::StartDeferredTaskRunners() {
+  GetBookmarkTaskRunner()->Start();
+}
diff --git a/chrome/browser/profiles/startup_task_runner_service.h b/chrome/browser/profiles/startup_task_runner_service.h
new file mode 100644
index 0000000..f6298a3
--- /dev/null
+++ b/chrome/browser/profiles/startup_task_runner_service.h
@@ -0,0 +1,45 @@
+// 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/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/threading/non_thread_safe.h"
+#include "chrome/browser/profiles/profile_keyed_service.h"
+
+class Profile;
+
+namespace base {
+class DeferredSequencedTaskRunner;
+}  // namespace base
+
+// This service manages the startup task runners.
+class StartupTaskRunnerService : public base::NonThreadSafe,
+                                 public ProfileKeyedService {
+ public:
+  explicit StartupTaskRunnerService(Profile* profile);
+  virtual ~StartupTaskRunnerService();
+
+  // Returns sequenced task runner where all bookmarks I/O operations are
+  // performed.
+  // This method should only be called from the UI thread.
+  // Note: Using a separate task runner per profile service gives a better
+  // management of the sequence in which the task are started in order to avoid
+  // congestion during start-up (e.g the caller may decide to start loading the
+  // bookmarks only after the history finished).
+  scoped_refptr<base::DeferredSequencedTaskRunner> GetBookmarkTaskRunner();
+
+  // 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_
diff --git a/chrome/browser/profiles/startup_task_runner_service_factory.cc b/chrome/browser/profiles/startup_task_runner_service_factory.cc
new file mode 100644
index 0000000..eaff6a8
--- /dev/null
+++ b/chrome/browser/profiles/startup_task_runner_service_factory.cc
@@ -0,0 +1,33 @@
+// 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 "chrome/browser/profiles/startup_task_runner_service_factory.h"
+
+#include "chrome/browser/profiles/profile_dependency_manager.h"
+#include "chrome/browser/profiles/startup_task_runner_service.h"
+
+StartupTaskRunnerServiceFactory::StartupTaskRunnerServiceFactory()
+    : ProfileKeyedServiceFactory("StartupTaskRunnerServiceFactory",
+                                 ProfileDependencyManager::GetInstance()) {
+}
+
+StartupTaskRunnerServiceFactory::~StartupTaskRunnerServiceFactory() {}
+
+// static
+StartupTaskRunnerService* StartupTaskRunnerServiceFactory::GetForProfile(
+    Profile* profile) {
+  return static_cast<StartupTaskRunnerService*>(
+      GetInstance()->GetServiceForProfile(profile, true));
+}
+
+// static
+StartupTaskRunnerServiceFactory*
+    StartupTaskRunnerServiceFactory::GetInstance() {
+  return Singleton<StartupTaskRunnerServiceFactory>::get();
+}
+
+ProfileKeyedService* StartupTaskRunnerServiceFactory::BuildServiceInstanceFor(
+    Profile* profile) const {
+  return new StartupTaskRunnerService(profile);
+}
diff --git a/chrome/browser/profiles/startup_task_runner_service_factory.h b/chrome/browser/profiles/startup_task_runner_service_factory.h
new file mode 100644
index 0000000..58bb4db
--- /dev/null
+++ b/chrome/browser/profiles/startup_task_runner_service_factory.h
@@ -0,0 +1,39 @@
+// 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_FACTORY_H_
+#define CHROME_BROWSER_PROFILES_STARTUP_TASK_RUNNER_SERVICE_FACTORY_H_
+
+#include "base/basictypes.h"
+#include "base/memory/singleton.h"
+#include "chrome/browser/profiles/profile_keyed_service_factory.h"
+
+class StartupTaskRunnerService;
+class PrefRegistrySyncable;
+class Profile;
+
+// Singleton that owns the start-up task runner service.
+class StartupTaskRunnerServiceFactory : public ProfileKeyedServiceFactory {
+ public:
+  // Returns the instance of StartupTaskRunnerService associated with this
+  // profile (creating one if none exists).
+  static StartupTaskRunnerService* GetForProfile(Profile* profile);
+
+  // Returns an instance of the StartupTaskRunnerServiceFactory singleton.
+  static StartupTaskRunnerServiceFactory* GetInstance();
+
+ private:
+  friend struct DefaultSingletonTraits<StartupTaskRunnerServiceFactory>;
+
+  StartupTaskRunnerServiceFactory();
+  virtual ~StartupTaskRunnerServiceFactory();
+
+  // ProfileKeyedServiceFactory:
+  virtual ProfileKeyedService* BuildServiceInstanceFor(
+      Profile* profile) const OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(StartupTaskRunnerServiceFactory);
+};
+
+#endif  // CHROME_BROWSER_PROFILES_STARTUP_TASK_RUNNER_SERVICE_FACTORY_H_
diff --git a/chrome/browser/sync/glue/bookmark_data_type_controller_unittest.cc b/chrome/browser/sync/glue/bookmark_data_type_controller_unittest.cc
index bfa351b..3f3e27b 100644
--- a/chrome/browser/sync/glue/bookmark_data_type_controller_unittest.cc
+++ b/chrome/browser/sync/glue/bookmark_data_type_controller_unittest.cc
@@ -56,7 +56,7 @@ class HistoryMock : public HistoryService {
 
 ProfileKeyedService* BuildBookmarkModel(Profile* profile) {
   BookmarkModel* bookmark_model = new BookmarkModel(profile);
-  bookmark_model->Load();
+  bookmark_model->Load(profile->GetIOTaskRunner());
   return bookmark_model;
 }
 
@@ -177,7 +177,7 @@ TEST_F(SyncBookmarkDataTypeControllerTest, StartBookmarkModelNotReady) {
                  base::Unretained(&model_load_callback_)));
   EXPECT_EQ(DataTypeController::MODEL_STARTING, bookmark_dtc_->state());
 
-  bookmark_model_->Load();
+  bookmark_model_->Load(profile_.GetIOTaskRunner());
   ui_test_utils::WaitForBookmarkModelToLoad(bookmark_model_);
   EXPECT_EQ(DataTypeController::MODEL_LOADED, bookmark_dtc_->state());
 
diff --git a/chrome/browser/sync/test/integration/sync_test.cc b/chrome/browser/sync/test/integration/sync_test.cc
index fbe9500..d2facba 100644
--- a/chrome/browser/sync/test/integration/sync_test.cc
+++ b/chrome/browser/sync/test/integration/sync_test.cc
@@ -231,7 +231,9 @@ Profile* SyncTest::MakeProfile(const base::FilePath::StringType name) {
 
   Profile* profile =
       Profile::CreateProfile(path, NULL, Profile::CREATE_MODE_SYNCHRONOUS);
-  g_browser_process->profile_manager()->RegisterTestingProfile(profile, true);
+  g_browser_process->profile_manager()->RegisterTestingProfile(profile,
+                                                               true,
+                                                               true);
   return profile;
 }
 
diff --git a/chrome/browser/ui/views/avatar_menu_button_browsertest.cc b/chrome/browser/ui/views/avatar_menu_button_browsertest.cc
index ca14d6e..498919c 100644
--- a/chrome/browser/ui/views/avatar_menu_button_browsertest.cc
+++ b/chrome/browser/ui/views/avatar_menu_button_browsertest.cc
@@ -25,7 +25,7 @@ void CreateTestingProfile() {
     CHECK(file_util::CreateDirectory(path));
   Profile* profile =
       Profile::CreateProfile(path, NULL, Profile::CREATE_MODE_SYNCHRONOUS);
-  profile_manager->RegisterTestingProfile(profile, true);
+  profile_manager->RegisterTestingProfile(profile, true, false);
 
   EXPECT_EQ(2u, profile_manager->GetNumberOfProfiles());
 }
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 1ea871f..46dda1a 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1536,6 +1536,10 @@
         'browser/profiles/refcounted_profile_keyed_service.h',
         'browser/profiles/refcounted_profile_keyed_service_factory.cc',
         'browser/profiles/refcounted_profile_keyed_service_factory.h',
+        'browser/profiles/startup_task_runner_service.cc',
+        'browser/profiles/startup_task_runner_service.h',
+        'browser/profiles/startup_task_runner_service_factory.cc',
+        'browser/profiles/startup_task_runner_service_factory.h',
         'browser/profiles/storage_partition_descriptor.h',
         'browser/remove_rows_table_model.h',
         'browser/renderer_host/chrome_render_message_filter.cc',
diff --git a/chrome/test/base/testing_profile.cc b/chrome/test/base/testing_profile.cc
index fed2377..92e1286 100644
--- a/chrome/test/base/testing_profile.cc
+++ b/chrome/test/base/testing_profile.cc
@@ -392,7 +392,7 @@ void TestingProfile::DestroyTopSites() {
 
 static ProfileKeyedService* BuildBookmarkModel(Profile* profile) {
   BookmarkModel* bookmark_model = new BookmarkModel(profile);
-  bookmark_model->Load();
+  bookmark_model->Load(profile->GetIOTaskRunner());
   return bookmark_model;
 }