[fsp] Simplify ID of provided file systems.

chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc

 // 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.
 
 #include "chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h"
 
 #include "chrome/browser/chromeos/file_system_provider/service.h"
 #include "chrome/common/extensions/api/file_system_provider.h"
 
 namespace extensions {
@@ skipping 33 matching lines @@
     result->Append(CreateError(kSecurityErrorName,
                                kEmptyNameErrorMessage));
     SetResult(result);
     return false;
   }
 
   chromeos::file_system_provider::Service* service =
       chromeos::file_system_provider::Service::Get(GetProfile());
   DCHECK(service);
 
-  const std::string file_system_id =
+  int file_system_id =
       service->RegisterFileSystem(extension_id(), params->display_name);
 
   // If the |file_system_id| is empty, then it means that registering the file

[satorux1, 2014/03/26 07:58:45]

zero

[mtomasz, 2014/03/26 09:30:15]

Done.

   // system failed.
   // TODO(mtomasz): Pass more detailed errors, rather than just a bool.
-  if (file_system_id.empty()) {
+  if (!file_system_id) {
     base::ListValue* result = new base::ListValue();
-    result->Append(new base::StringValue(""));
+    result->Append(new base::FundamentalValue(0));
     result->Append(
         CreateError(kSecurityErrorName, kRegisteringFailedErrorMessage));
     SetResult(result);
     return false;
   }
 
   base::ListValue* result = new base::ListValue();
-  result->Append(new base::StringValue(file_system_id));
+  result->Append(new base::FundamentalValue(file_system_id));
   // Don't append an error on success.
 
   SetResult(result);
   SendResponse(true);
   return true;
 }
 
 }  // namespace extensions