Implement the calls to GAIA for the IDP IFrame protocol.

google_apis/gaia/gaia_urls.h

Index: google_apis/gaia/gaia_urls.h
diff --git a/google_apis/gaia/gaia_urls.h b/google_apis/gaia/gaia_urls.h
index 55080d9394d74b1c4ce06c662d3fb2bbdd4189b6..f41e41c527ec838dccbcd007128beb2255880f79 100644
--- a/google_apis/gaia/gaia_urls.h
+++ b/google_apis/gaia/gaia_urls.h
@@ -43,6 +43,7 @@ class GaiaUrls {
   const GURL& oauth2_issue_token_url() const;
   const GURL& oauth2_token_info_url() const;
   const GURL& oauth2_revoke_url() const;
+  const GURL& oauth2_iframe_url() const;
 
   const GURL& gaia_login_form_realm() const;
 
@@ -89,6 +90,7 @@ class GaiaUrls {
   GURL oauth2_issue_token_url_;
   GURL oauth2_token_info_url_;
   GURL oauth2_revoke_url_;
+  GURL oauth2_iframe_url_;
 
   GURL gaia_login_form_realm_;