[fsp] Add support for opening files.

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 "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"
@@ skipping 20 matching lines @@
 
   // ProvidedFileSystemInterface overrides.
   virtual void RequestUnmount(
       const fileapi::AsyncFileUtil::StatusCallback& callback) OVERRIDE;
   virtual void GetMetadata(
       const base::FilePath& entry_path,
       const fileapi::AsyncFileUtil::GetFileInfoCallback& callback) OVERRIDE;
   virtual void ReadDirectory(
       const base::FilePath& directory_path,
       const fileapi::AsyncFileUtil::ReadDirectoryCallback& callback) OVERRIDE;
+  virtual void OpenFile(
+      const base::FilePath& file_path,
+      OpenFileMode mode,
+      bool create,
+      const fileapi::AsyncFileUtil::StatusCallback& callback) OVERRIDE;
   virtual const ProvidedFileSystemInfo& GetFileSystemInfo() const OVERRIDE;
   virtual RequestManager* GetRequestManager() OVERRIDE;
 
  private:
   extensions::EventRouter* event_router_;
   RequestManager request_manager_;
   ProvidedFileSystemInfo file_system_info_;
 
   DISALLOW_COPY_AND_ASSIGN(ProvidedFileSystem);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_PROVIDED_FILE_SYSTEM_H_