Part 1 of work to do user sign in based on OAuth2:

chrome/common/net/gaia/gaia_urls.h

Index: chrome/common/net/gaia/gaia_urls.h
===================================================================
--- chrome/common/net/gaia/gaia_urls.h	(revision 110361)
+++ chrome/common/net/gaia/gaia_urls.h	(working copy)
@@ -34,6 +34,11 @@
   const std::string& oauth1_login_scope();
   const std::string& oauth_wrap_bridge_user_info_scope();
 
+  const std::string& oauth2_chrome_client_id();
+  const std::string& oauth2_chrome_client_secret();
+  const std::string& client_login_to_oauth2_url();
+  const std::string& oauth2_token_url();
+
  private:
   GaiaUrls();
   ~GaiaUrls();
@@ -58,6 +63,11 @@
   std::string oauth1_login_scope_;
   std::string oauth_wrap_bridge_user_info_scope_;
 
+  std::string oauth2_chrome_client_id_;
+  std::string oauth2_chrome_client_secret_;
+  std::string client_login_to_oauth2_url_;
+  std::string oauth2_token_url_;
+
   DISALLOW_COPY_AND_ASSIGN(GaiaUrls);
 };