Change webkit/{fileapi,quota} code to use TaskRunner.

webkit/fileapi/file_system_file_reader.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_FILEAPI_FILE_SYSTEM_FILE_READER_H_
 #define WEBKIT_FILEAPI_FILE_SYSTEM_FILE_READER_H_
 #pragma once
 
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/platform_file.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/blob/file_reader.h"
 
 class FilePath;
 
 namespace base {
-class MessageLoopProxy;
+class SequencedTaskRunner;
 }
 
 namespace webkit_blob {
 class LocalFileReader;
 class ShareableFileReference;
 }
 
 namespace fileapi {
 
 class FileSystemContext;
 
 // TODO(kinaba,satorux): This generic implementation would work for any
 // filesystems but remote filesystem should implement its own reader
 // rather than relying on FileSystemOperation::GetSnapshotFile() which
 // may force downloading the entire contents for remote files.
 class FileSystemFileReader : public webkit_blob::FileReader {
  public:
   // Creates a new FileReader for a filesystem URL |url| form |initial_offset|.
-  FileSystemFileReader(base::MessageLoopProxy* file_thread_proxy,
+  FileSystemFileReader(base::SequencedTaskRunner* task_runner,
                        FileSystemContext* file_system_context,
                        const GURL& url,
                        int64 initial_offset);
   virtual ~FileSystemFileReader();
 
   // FileReader override.
   virtual int Read(net::IOBuffer* buf, int buf_len,
                    const net::CompletionCallback& callback) OVERRIDE;
 
  private:
   void DidCreateSnapshot(
       const base::Closure& read_closure,
       const net::CompletionCallback& callback,
       base::PlatformFileError file_error,
       const base::PlatformFileInfo& file_info,
       const FilePath& platform_path,
       const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref);
 
-  scoped_refptr<base::MessageLoopProxy> file_thread_proxy_;
+  scoped_refptr<base::SequencedTaskRunner> task_runner_;
   scoped_refptr<FileSystemContext> file_system_context_;
   const GURL url_;
   const int64 initial_offset_;
   scoped_ptr<webkit_blob::LocalFileReader> local_file_reader_;
   scoped_refptr<webkit_blob::ShareableFileReference> snapshot_ref_;
   bool has_pending_create_snapshot_;
   base::WeakPtrFactory<FileSystemFileReader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemFileReader);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_FILE_READER_H_