This is UI side unreadable device support.

chrome/browser/extensions/extension_function_dispatcher.cc

 // Copyright (c) 2011 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/extensions/extension_function_dispatcher.h"
 
 #include <map>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
@@ skipping 353 matching lines @@
   RegisterFunction<GetVolumeMetadataFunction>();
   RegisterFunction<RequestLocalFileSystemFunction>();
   RegisterFunction<AddFileWatchBrowserFunction>();
   RegisterFunction<RemoveFileWatchBrowserFunction>();
   RegisterFunction<SelectFileFunction>();
   RegisterFunction<SelectFilesFunction>();
   RegisterFunction<AddMountFunction>();
   RegisterFunction<RemoveMountFunction>();
   RegisterFunction<GetMountPointsFunction>();
   RegisterFunction<FormatDeviceFunction>();
+  RegisterFunction<FormatUnmountedDeviceFunction>();
   RegisterFunction<ViewFilesFunction>();
 
   // Mediaplayer
   RegisterFunction<PlayAtMediaplayerFunction>();
   RegisterFunction<SetPlaybackErrorMediaplayerFunction>();
   RegisterFunction<GetPlaylistMediaplayerFunction>();
   RegisterFunction<TogglePlaylistPanelMediaplayerFunction>();
   RegisterFunction<ToggleFullscreenMediaplayerFunction>();
 
   // InputMethod
@@ skipping 263 matching lines @@
   return function;
 }
 
 // static
 void ExtensionFunctionDispatcher::SendAccessDenied(
     IPC::Message::Sender* ipc_sender, int routing_id, int request_id) {
   ipc_sender->Send(new ExtensionMsg_Response(
       routing_id, request_id, false, std::string(),
       "Access to extension API denied."));
 }