Google RequestForAccessToken raises Bad Request / ProtocolError

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Using the 2.3.1 patch and Google authentication to get contacts.
2. In OAuth1_0Hybrid, RequestForAccessToken()
3. At (HttpWebResponse)httpWebRequest.GetResponse()

What is the expected output? What do you see instead?
I'm getting this response: The remote server returned an error: (400) Bad 
Request.
Exception status: System.Net.WebExceptionStatus.ProtocolError

What version of the product are you using? On what operating system?
2.3.1, MVC4, Win7.

Please provide any additional information below.
AccessTokenEndpoint is: https://www.google.com/accounts/OAuthGetAccessToken

These query parameters are used:
oauth_consumer_key, oauth_token, oauth_signature_method, oauth_timestamp, 
oauth_nonce, oauth_version, oauth_signature

Original issue reported on code.google.com by fm0...@gmail.com on 20 Jun 2013 at 8:44

[GoogleCodeExporter]

With logging enabled, the output was:

[(null)]    DEBUG   IOAuth1_0Hybrid Requesting Access Token at: 
https://www.google.com/accounts/OAuthGetAccessToken?[ommitted]
Request Parameters: [ommitted]
[(null)]    DEBUG   IOAuth1_0Hybrid An error occurred while requesting Access Token 
at https://www.google.com/accounts/OAuthGetAccessToken?[ommitted]
with parameters [ommitted]
System.Net.WebException: The remote server returned an error: (400) Bad Request.
   at System.Net.HttpWebRequest.GetResponse()
   at Brickred.SocialAuth.NET.Core.OAuth1_0Hybrid.RequestForAccessToken()

Original comment by fm0...@gmail.com on 21 Jun 2013 at 1:46