This is UI side unreadable device support.

chrome/browser/ui/webui/fileicon_source_cros.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/ui/webui/fileicon_source_cros.h"
 
 #include <map>
 #include <utility>
 #include <vector>
 
@@ skipping 34 matching lines @@
   std::make_pair("small", IconLoader::SMALL),
   std::make_pair("normal", IconLoader::NORMAL),
   std::make_pair("large", IconLoader::LARGE)
 };
 
 const IdrBySize kAudioIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_AUDIO,
   IDR_FILE_MANAGER_IMG_FILETYPE_LARGE_AUDIO,
   IDR_FILE_MANAGER_IMG_FILETYPE_LARGE_AUDIO
 };
+const IdrBySize kDeviceIdrs = {
+  IDR_FILE_MANAGER_IMG_FILETYPE_DEVICE,
+  IDR_FILE_MANAGER_IMG_FILETYPE_DEVICE,
+  IDR_FILE_MANAGER_IMG_FILETYPE_DEVICE
+};
 const IdrBySize kDocIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_DOC,
   IDR_FILE_MANAGER_IMG_FILETYPE_DOC,
   IDR_FILE_MANAGER_IMG_FILETYPE_DOC
 };
 const IdrBySize kFolderIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_FOLDER,
   IDR_FILE_MANAGER_IMG_FILETYPE_LARGE_FOLDER,
   IDR_FILE_MANAGER_IMG_FILETYPE_LARGE_FOLDER
 };
@@ skipping 20 matching lines @@
 const IdrBySize kPresentationIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_PRESENTATION,
   IDR_FILE_MANAGER_IMG_FILETYPE_PRESENTATION,
   IDR_FILE_MANAGER_IMG_FILETYPE_PRESENTATION
 };
 const IdrBySize kSpreadsheetIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_SPREADSHEET,
   IDR_FILE_MANAGER_IMG_FILETYPE_SPREADSHEET,
   IDR_FILE_MANAGER_IMG_FILETYPE_SPREADSHEET
 };
+const IdrBySize kUnreadableDeviceIdrs = {
+  IDR_FILE_MANAGER_IMG_FILETYPE_UNREADABLE_DEVICE,
+  IDR_FILE_MANAGER_IMG_FILETYPE_UNREADABLE_DEVICE,
+  IDR_FILE_MANAGER_IMG_FILETYPE_UNREADABLE_DEVICE
+};
 const IdrBySize kTextIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_TEXT,
   IDR_FILE_MANAGER_IMG_FILETYPE_TEXT,
   IDR_FILE_MANAGER_IMG_FILETYPE_TEXT
 };
 const IdrBySize kVideoIdrs = {
   IDR_FILE_MANAGER_IMG_FILETYPE_VIDEO,
   IDR_FILE_MANAGER_IMG_FILETYPE_LARGE_VIDEO,
   IDR_FILE_MANAGER_IMG_FILETYPE_LARGE_VIDEO
 };
@@ skipping 132 matching lines @@
   scoped_refptr<RefCountedStaticMemory> bytes(rb.LoadDataResourceBytes(idr));
   SendResponse(request_id, bytes);
 }
 
 // The mime type refers to the type of the response/icon served.
 std::string FileIconSourceCros::GetMimeType(
     const std::string& url) const {
   return "image/png";
 }