facebook-csharp-sdk/facebook-csharp-sdk — pull request #200 by mingulov (2012-10-12 16:39:51+00:00)
Title: Use custom DeserializeJson for text/plain /oauth/access_token results also

It is possible to setup own DeserializeJson method.

It should be used everywhere, for /oauth/access_token result also - as otherwise it might be that the client does not expect to receive JsonObject created by SimpleJson - and wants its own data (which might be just a simple string, for example, if client has its own JSON parser).