[ew] Add basic classes.

chrome/browser/chromeos/drive/fileapi/file_system_backend_delegate.h

 // Copyright 2014 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_CHROMEOS_DRIVE_FILEAPI_FILE_SYSTEM_BACKEND_DELEGATE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILEAPI_FILE_SYSTEM_BACKEND_DELEGATE_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/fileapi/file_system_backend_delegate.h"
 
 namespace fileapi {
 class AsyncFileUtil;
+class FileSystemContext;
+class FileSystemURL;
+class FileStreamWriter;
+class WatcherManager;
 }  // namespace fileapi
 
+namespace webkit_blob {
+class FileStreamReader;
+}  // namespace webkit_blob
+
 namespace drive {
 
 // Delegate implementation of the some methods in chromeos::FileSystemBackend
 // for Drive file system.
 class FileSystemBackendDelegate : public chromeos::FileSystemBackendDelegate {
  public:
   FileSystemBackendDelegate();
   virtual ~FileSystemBackendDelegate();
 
   // FileSystemBackend::Delegate overrides.
   virtual fileapi::AsyncFileUtil* GetAsyncFileUtil(
       fileapi::FileSystemType type) OVERRIDE;
   virtual scoped_ptr<webkit_blob::FileStreamReader> CreateFileStreamReader(
       const fileapi::FileSystemURL& url,
       int64 offset,
       const base::Time& expected_modification_time,
       fileapi::FileSystemContext* context) OVERRIDE;
   virtual scoped_ptr<fileapi::FileStreamWriter> CreateFileStreamWriter(
       const fileapi::FileSystemURL& url,
       int64 offset,
       fileapi::FileSystemContext* context) OVERRIDE;
+  virtual fileapi::WatcherManager* GetWatcherManager(
+      const fileapi::FileSystemURL& url) OVERRIDE;
 
  private:
   scoped_ptr<fileapi::AsyncFileUtil> async_file_util_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemBackendDelegate);
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILEAPI_FILE_SYSTEM_BACKEND_DELEGATE_H_