Support for auth code based authentication flow for both app and web UI driven flow.

google_apis/gaia/gaia_auth_fetcher.h

Index: google_apis/gaia/gaia_auth_fetcher.h
diff --git a/google_apis/gaia/gaia_auth_fetcher.h b/google_apis/gaia/gaia_auth_fetcher.h
index 942bb7b297906df1c098b67a0e9ea53e333419f2..06ff3295271bc01306c36991f9ea03876a721479 100644
--- a/google_apis/gaia/gaia_auth_fetcher.h
+++ b/google_apis/gaia/gaia_auth_fetcher.h
@@ -109,6 +109,13 @@ class GaiaAuthFetcher : public net::URLFetcherDelegate {
   // called on the consumer on the original thread.
   void StartCookieForOAuthLoginTokenExchange(const std::string& session_index);
 
+  // Start a request to exchange the authorization code for an OAuthLogin-scoped
+  // oauth2 token.
+  //
+  // Either OnClientOAuthSuccess or OnClientOAuthFailure will be
+  // called on the consumer on the original thread.
+  void StartAuthCodeForOAuth2TokenExchange(const std::string& auth_code);
+
   // Start a request to get user info for the account identified by |lsid|.
   //
   // Either OnGetUserInfoSuccess or OnGetUserInfoFailure will be
@@ -357,8 +364,6 @@ class GaiaAuthFetcher : public net::URLFetcherDelegate {
   static std::string MakeOAuthLoginBody(const std::string& service,
                                         const std::string& source);
 
-  void StartOAuth2TokenPairFetch(const std::string& auth_code);
-
   // Create a fetcher usable for making any Gaia request.  |body| is used
   // as the body of the POST request sent to GAIA.  Any strings listed in
   // |headers| are added as extra HTTP headers in the request.