Add name of the enum to message to help looking up.

chromeos/cryptohome/homedir_methods.cc

 // 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.
 
 #include "chromeos/cryptohome/homedir_methods.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 393 matching lines @@
   void OnMountExCallback(const MountCallback& callback,
                          chromeos::DBusMethodCallStatus call_status,
                          bool result,
                          const BaseReply& reply) {
     if (call_status != chromeos::DBUS_METHOD_CALL_SUCCESS) {
       callback.Run(false, MOUNT_ERROR_FATAL, std::string());
       return;
     }
     if (reply.has_error()) {
       if (reply.error() != CRYPTOHOME_ERROR_NOT_SET) {
-        LOGIN_LOG(ERROR) << "HomedirMethods MountEx error: " << reply.error();
+        LOGIN_LOG(ERROR)
+            << "HomedirMethods MountEx error (CryptohomeErrorCode): "
+            << reply.error();
         callback.Run(false, MapError(reply.error()), std::string());
         return;
       }
     }
     if (!reply.HasExtension(MountReply::reply)) {
       callback.Run(false, MOUNT_ERROR_FATAL, std::string());
       return;
     }
 
     std::string mount_hash;
@@ skipping 82 matching lines @@
   }
   delete g_homedir_methods;
   g_homedir_methods = NULL;
   VLOG(1) << "HomedirMethods Shutdown completed";
 }
 
 // static
 HomedirMethods* HomedirMethods::GetInstance() { return g_homedir_methods; }
 
 }  // namespace cryptohome