Don't crash browser process when OK passed as error code in FSP API.

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 <memory>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 330 matching lines @@
           RequestValue::CreateForOperationSuccess(std::move(params))),
       false /* has_more */);
 }
 
 ExtensionFunction::ResponseAction
 FileSystemProviderInternalOperationRequestedErrorFunction::Run() {
   using api::file_system_provider_internal::OperationRequestedError::Params;
   std::unique_ptr<Params> params(Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params);
 
+  if (params->error == api::file_system_provider::PROVIDER_ERROR_OK) {
+    // It's incorrect to pass OK as an error code.
+    return ValidationFailure(this);
+  }
+
   const base::File::Error error = ProviderErrorToFileError(params->error);
   return RejectRequest(RequestValue::CreateForOperationError(std::move(params)),
                        error);
 }
 
 }  // namespace extensions