Display local signin error without browser and record the path of selected profile in user manager.

chrome/browser/ui/webui/signin/user_manager_screen_handler.cc

Index: chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
diff --git a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
index a56bbe86f0f4b62d786d9c086bb32c4b41c3cbb3..286608b7dae19cb53c709a9ee54eb8047d80f29d 100644
--- a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
+++ b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
@@ -469,11 +469,17 @@ void UserManagerScreenHandler::HandleAuthenticatedLaunchUser(
     }
   }
 
-  // In order to support the upgrade case where we have a local hash but no
-  // password token, the user perform a full online reauth.
-  UserManager::ShowReauthDialog(web_ui()->GetWebContents()->GetBrowserContext(),
-                                email_address_,
-                                signin_metrics::Reason::REASON_UNLOCK);
+  content::BrowserContext* browser_context =
+      web_ui()->GetWebContents()->GetBrowserContext();
+  if (!email_address_.empty()) {
+    // In order to support the upgrade case where we have a local hash but no
+    // password token, the user perform a full online reauth.
+    UserManager::ShowReauthDialog(browser_context, email_address_,
+                                  signin_metrics::Reason::REASON_UNLOCK);
+  } else {
+    // Fresh sign in via user manager without existed email address.
+    UserManager::ShowSigninDialog(browser_context, profile_path);
+  }
 }
 
 void UserManagerScreenHandler::HandleRemoveUser(const base::ListValue* args) {