Remove drive::FileSystemInterface::Initialize().

chrome/browser/chromeos/drive/file_system.cc

 // 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_system.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/platform_file.h"
 #include "base/prefs/pref_service.h"
@@ skipping 255 matching lines @@
 
   ResetComponents();
 }
 
 FileSystem::~FileSystem() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   change_list_loader_->RemoveObserver(this);
 }
 
-void FileSystem::Initialize() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-}
-
 void FileSystem::Reload(const FileOperationCallback& callback) {
   // Discard the current loader and operation objects and renew them. This is to
   // avoid that changes initiated before the metadata reset is applied after the
   // reset, which may cause an inconsistent state.
   // TODO(kinaba): callbacks held in the subcomponents are discarded. We might
   // want to have a way to abort and flush callbacks in in-flight operations.
   ResetComponents();
 
   base::PostTaskAndReplyWithResult(
       blocking_task_runner_,
@@ skipping 771 matching lines @@
   if (util::IsSpecialResourceId(id))
     return;
 
   util::Log(logging::LOG_INFO,
             "Thumbnail refresh for %s", directory_path.AsUTF8Unsafe().c_str());
   change_list_loader_->LoadDirectoryFromServer(
       id, base::Bind(&util::EmptyFileOperationCallback));
 }
 
 }  // namespace drive