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

google_apis/gaia/gaia_urls.cc

Index: google_apis/gaia/gaia_urls.cc
diff --git a/google_apis/gaia/gaia_urls.cc b/google_apis/gaia/gaia_urls.cc
index acb4c19e38a46bb1b80bb41853aabebbfcae9ec8..1ba0a10ca1b1c24c534428ebc58da51d4a0f399d 100644
--- a/google_apis/gaia/gaia_urls.cc
+++ b/google_apis/gaia/gaia_urls.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "base/strings/stringprintf.h"
 #include "google_apis/gaia/gaia_switches.h"
 #include "google_apis/google_api_keys.h"
 
@@ -245,3 +246,20 @@ const GURL& GaiaUrls::oauth2_revoke_url() const {
 const GURL& GaiaUrls::gaia_login_form_realm() const {
   return gaia_url_;
 }
+
+GURL GaiaUrls::ListAccountsURLWithSource(const std::string& source) {
+  if (source.empty()) {
+    return list_accounts_url();
+  } else {
+    std::string query = list_accounts_url().query();
+    return list_accounts_url().Resolve(
+        base::StringPrintf("?source=%s&%s", source.c_str(), query.c_str()));
+  }
+}
+
+GURL GaiaUrls::GetCheckConnectionInfoURLWithSource(const std::string& source) {
+  return source.empty()
+      ? get_check_connection_info_url()
+      : get_check_connection_info_url().Resolve(
+            base::StringPrintf("?source=%s", source.c_str()));
+}