Convert drive::FileWriteHelper to a single function for simplification.

chrome/browser/chromeos/drive/file_write_helper.cc

Index: chrome/browser/chromeos/drive/file_write_helper.cc
diff --git a/chrome/browser/chromeos/drive/file_write_helper.cc b/chrome/browser/chromeos/drive/file_write_helper.cc
deleted file mode 100644
index b5623edb896502ad314343467945ac244c3e1187..0000000000000000000000000000000000000000
--- a/chrome/browser/chromeos/drive/file_write_helper.cc
+++ /dev/null
@@ -1,63 +0,0 @@
-// 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.
-
-#include "chrome/browser/chromeos/drive/file_write_helper.h"
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/threading/sequenced_worker_pool.h"
-#include "chrome/browser/chromeos/drive/file_system_interface.h"
-#include "content/public/browser/browser_thread.h"
-
-using content::BrowserThread;
-
-namespace drive {
-
-FileWriteHelper::FileWriteHelper(FileSystemInterface* file_system)
-    : file_system_(file_system),
-      weak_ptr_factory_(this) {
-  // Must be created in DriveIntegrationService.
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-}
-
-FileWriteHelper::~FileWriteHelper() {
-  // Must be destroyed in DriveIntegrationService.
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-}
-
-void FileWriteHelper::PrepareWritableFileAndRun(
-    const base::FilePath& file_path,
-    const OpenFileCallback& callback) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK(!callback.is_null());
-
-  file_system_->OpenFile(
-      file_path, OPEN_OR_CREATE_FILE,
-      base::Bind(&FileWriteHelper::PrepareWritableFileAndRunAfterOpenFile,
-                 weak_ptr_factory_.GetWeakPtr(), file_path, callback));
-}
-
-void FileWriteHelper::PrepareWritableFileAndRunAfterOpenFile(
-    const base::FilePath& file_path,
-    const OpenFileCallback& callback,
-    FileError error,
-    const base::FilePath& local_cache_path,
-    const base::Closure& close_callback) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK(!callback.is_null());
-
-  if (error != FILE_ERROR_OK) {
-    content::BrowserThread::GetBlockingPool()->PostTask(
-        FROM_HERE,
-        base::Bind(callback, error, base::FilePath()));
-    return;
-  }
-
-  content::BrowserThread::GetBlockingPool()->PostTaskAndReply(
-      FROM_HERE,
-      base::Bind(callback, FILE_ERROR_OK, local_cache_path),
-      close_callback);
-}
-
-}  // namespace drive