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

Index: chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
diff --git a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
index 80d27f085008aa1a8163d7adf85734e5ace536fd..8db2cbc3de2cd3fd2217eb9cfdf0997db0af47bc 100644
--- a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
+++ b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.cc
@@ -348,6 +348,11 @@ FileSystemProviderInternalOperationRequestedErrorFunction::Run() {
   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);