[fsp] Add FileStreamReader for the reading operation.

chrome/browser/chromeos/file_system_provider/provided_file_system.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_FILE_SYSTEM_PROVIDER_PROVIDED_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_PROVIDED_FILE_SYSTEM_H_
 
+#include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
 #include "chrome/browser/chromeos/file_system_provider/request_manager.h"
 #include "webkit/browser/fileapi/async_file_util.h"
 
 namespace net {
 class IOBuffer;
 }  // namespace net
 
 namespace base {
@@ skipping 31 matching lines @@
   virtual void CloseFile(
       int file_handle,
       const fileapi::AsyncFileUtil::StatusCallback& callback) OVERRIDE;
   virtual void ReadFile(int file_handle,
                         net::IOBuffer* buffer,
                         int64 offset,
                         int length,
                         const ReadChunkReceivedCallback& callback) OVERRIDE;
   virtual const ProvidedFileSystemInfo& GetFileSystemInfo() const OVERRIDE;
   virtual RequestManager* GetRequestManager() OVERRIDE;
+  virtual base::WeakPtr<ProvidedFileSystemInterface> GetWeakPtr() OVERRIDE;
 
  private:
   extensions::EventRouter* event_router_;
   RequestManager request_manager_;
   ProvidedFileSystemInfo file_system_info_;
 
+  base::WeakPtrFactory<ProvidedFileSystemInterface> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(ProvidedFileSystem);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_PROVIDED_FILE_SYSTEM_H_