Use a distinct source parameter on gaia endpoints for the reconcilor.

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 57afc22faadda3681dbb8fd03f404a8bdc25d076..b7b6b976343df9b75e1a0ecef7d707c1e3da74fa 100644
--- a/google_apis/gaia/gaia_auth_fetcher.h
+++ b/google_apis/gaia/gaia_auth_fetcher.h
@@ -44,6 +44,10 @@ class GaiaAuthFetcher : public net::URLFetcherDelegate {
   // needed to complete authentication, the user provided the right password.
   static const char kSecondFactor[];
 
+  // Build URLs for these endpoints with the given source parameter.
+  static GURL BuildListAccountsURL(const std::string& source);
+  static GURL BuildGetCheckConnectionInfoURL(const std::string& source);
+
   // This will later be hidden behind an auth service which caches
   // tokens.
   GaiaAuthFetcher(GaiaAuthConsumer* consumer,
@@ -389,7 +393,7 @@ class GaiaAuthFetcher : public net::URLFetcherDelegate {
       const std::string& data,
       const net::URLRequestStatus& status);
 
-  // These fields are common to GaiaAuthFetcher, same every request
+  // These fields are common to GaiaAuthFetcher, same every request.
   GaiaAuthConsumer* const consumer_;
   net::URLRequestContextGetter* const getter_;
   std::string source_;