This is UI side unreadable device support.

chrome/browser/chromeos/cros/mount_library.h

Index: chrome/browser/chromeos/cros/mount_library.h
diff --git a/chrome/browser/chromeos/cros/mount_library.h b/chrome/browser/chromeos/cros/mount_library.h
index 688c8b1848b18545c0332506cf5e7d955f3d98db..bd25cdbecbc042ef57b3dafa450aa0dab53bfbb3 100644
--- a/chrome/browser/chromeos/cros/mount_library.h
+++ b/chrome/browser/chromeos/cros/mount_library.h
@@ -135,11 +135,14 @@ class MountLibrary {
     std::string source_path;
     std::string mount_path;
     MountType mount_type;
+    std::string special_data;
 
-    MountPointInfo(const char* source, const char* mount, const MountType type)
+    MountPointInfo(const char* source, const char* mount, const MountType type,
+        const char* special)
         : source_path(source ? source : ""),
           mount_path(mount ? mount : ""),
-          mount_type(type) {
+          mount_type(type),
+          special_data(special ? special : "") {
     }
   };
 
@@ -155,7 +158,7 @@ class MountLibrary {
     virtual void DiskChanged(MountLibraryEventType event,
                              const Disk* disk) = 0;
     virtual void DeviceChanged(MountLibraryEventType event,
-                               const std::string& device_path ) = 0;
+                               const std::string& device_path) = 0;
     virtual void MountCompleted(MountEvent event_type,
                                 MountError error_code,
                                 const MountPointInfo& mount_info) = 0;