[fsp] Introduce file_system_provider::Service class for the FileSystemProvider API.

chrome/common/extensions/api/file_browser_private.idl

 // Copyright 2013 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.
 
 // fileBrowserPrivate API.
 // This is a private API used by the file browser of ChromeOS.
 [platforms=("chromeos"),
  implemented_in="chrome/browser/chromeos/extensions/file_manager/file_browser_private_api_functions.h"]
 namespace fileBrowserPrivate {
 // Type of the mounted volume.
-enum VolumeType { drive, downloads, removable, archive, cloud_device, testing };
+enum VolumeType { drive, downloads, removable, archive, cloud_device, provided,
+                  testing };
 
 // Device type. Available if this is removable volume.
 enum DeviceType { usb, sd, optical, mobile, unknown };
 
 // Additional data about mount, for example, that the filesystem is not
 // supported.
 enum MountCondition { unknown, unsupported };
 
 // Is the event raised for mounting or unmounting.
 enum MountCompletedEventType { mount, unmount };
@@ skipping 722 matching lines @@
   static void onDriveSyncError(DriveSyncErrorEvent event);
 
   // Dispatched when a profile is added.
   static void onProfileAdded();
 
   // Dispatched when any window moves another desktop.
   // TODO(hirono): Add information which window is moved.
   static void onDesktopChanged();
 };
 };