Move webkit/{browser,common}/dom_storage into content/

webkit/browser/dom_storage/dom_storage_task_runner.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 WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_TASK_RUNNER_
-#define WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_TASK_RUNNER_
-
-#include "base/memory/ref_counted.h"
-#include "base/sequenced_task_runner.h"
-#include "base/threading/sequenced_worker_pool.h"
-#include "base/time/time.h"
-#include "webkit/browser/webkit_storage_browser_export.h"
-
-namespace base {
-class MessageLoopProxy;
-}
-
-namespace dom_storage {
-
-// DomStorage uses two task sequences (primary vs commit) to avoid
-// primary access from queuing up behind commits to disk.
-// * Initialization, shutdown, and administrative tasks are performed as
-//   shutdown-blocking primary sequence tasks.
-// * Tasks directly related to the javascript'able interface are performed
-//   as shutdown-blocking primary sequence tasks.
-//   TODO(michaeln): Skip tasks for reading during shutdown.
-// * Internal tasks related to committing changes to disk are performed as
-//   shutdown-blocking commit sequence tasks.
-class WEBKIT_STORAGE_BROWSER_EXPORT DomStorageTaskRunner
-    : public base::TaskRunner {
- public:
-  enum SequenceID {
-    PRIMARY_SEQUENCE,
-    COMMIT_SEQUENCE
-  };
-
-  // The PostTask() and PostDelayedTask() methods defined by TaskRunner
-  // post shutdown-blocking tasks on the primary sequence.
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      base::TimeDelta delay) = 0;
-
-  // Posts a shutdown blocking task to |sequence_id|.
-  virtual bool PostShutdownBlockingTask(
-      const tracked_objects::Location& from_here,
-      SequenceID sequence_id,
-      const base::Closure& task) = 0;
-
-  // The TaskRunner override returns true if the current thread is running
-  // on the primary sequence.
-  virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
-
-  // Returns true if the current thread is running on the given |sequence_id|.
-  virtual bool IsRunningOnSequence(SequenceID sequence_id) const = 0;
-  bool IsRunningOnPrimarySequence() const {
-    return IsRunningOnSequence(PRIMARY_SEQUENCE);
-  }
-  bool IsRunningOnCommitSequence() const {
-    return IsRunningOnSequence(COMMIT_SEQUENCE);
-  }
-
- protected:
-  virtual ~DomStorageTaskRunner() {}
-};
-
-// A derived class used in chromium that utilizes a SequenceWorkerPool
-// under dom_storage specific SequenceTokens. The |delayed_task_loop|
-// is used to delay scheduling on the worker pool.
-class WEBKIT_STORAGE_BROWSER_EXPORT DomStorageWorkerPoolTaskRunner :
-      public DomStorageTaskRunner {
- public:
-  DomStorageWorkerPoolTaskRunner(
-      base::SequencedWorkerPool* sequenced_worker_pool,
-      base::SequencedWorkerPool::SequenceToken primary_sequence_token,
-      base::SequencedWorkerPool::SequenceToken commit_sequence_token,
-      base::MessageLoopProxy* delayed_task_loop);
-
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      base::TimeDelta delay) OVERRIDE;
-
-  virtual bool PostShutdownBlockingTask(
-      const tracked_objects::Location& from_here,
-      SequenceID sequence_id,
-      const base::Closure& task) OVERRIDE;
-
-  virtual bool IsRunningOnSequence(SequenceID sequence_id) const OVERRIDE;
-
- protected:
-  virtual ~DomStorageWorkerPoolTaskRunner();
-
- private:
-
-  base::SequencedWorkerPool::SequenceToken IDtoToken(SequenceID id) const;
-
-  const scoped_refptr<base::MessageLoopProxy> message_loop_;
-  const scoped_refptr<base::SequencedWorkerPool> sequenced_worker_pool_;
-  base::SequencedWorkerPool::SequenceToken primary_sequence_token_;
-  base::SequencedWorkerPool::SequenceToken commit_sequence_token_;
-};
-
-// A derived class used in unit tests that ignores all delays so
-// we don't block in unit tests waiting for timeouts to expire.
-// There is no distinction between [non]-shutdown-blocking or
-// the primary sequence vs the commit sequence in the mock,
-// all tasks are scheduled on |message_loop| with zero delay.
-class WEBKIT_STORAGE_BROWSER_EXPORT MockDomStorageTaskRunner :
-      public DomStorageTaskRunner {
- public:
-  explicit MockDomStorageTaskRunner(base::MessageLoopProxy* message_loop);
-
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      base::TimeDelta delay) OVERRIDE;
-
-  virtual bool PostShutdownBlockingTask(
-      const tracked_objects::Location& from_here,
-      SequenceID sequence_id,
-      const base::Closure& task) OVERRIDE;
-
-  virtual bool IsRunningOnSequence(SequenceID sequence_id) const OVERRIDE;
-
- protected:
-  virtual ~MockDomStorageTaskRunner();
-
- private:
-  const scoped_refptr<base::MessageLoopProxy> message_loop_;
-};
-
-}  // namespace dom_storage
-
-#endif  // WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_TASK_RUNNER_