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

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/signin/user_manager_screen_handler.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
@@ skipping 451 matching lines @@
                   GetURLRequestContext()));
     }
 
     const std::string token = entry->GetPasswordChangeDetectionToken();
     if (!token.empty()) {
       oauth_client_->GetTokenHandleInfo(token, kMaxOAuthRetries, this);
       return;
     }
   }
 
-  // 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_,
+  content::BrowserContext* browser_context =
+      web_ui()->GetWebContents()->GetBrowserContext();
+
+#if !defined(OS_MACOSX)

[tommycli, 2016/09/21 18:26:59]

Why the mac vs. non-mac distinction?

Also the non-mac version lost the comment. Maybe the comment should be at the
top level.

[zmin, 2016/09/21 21:21:37]

Because the user_manager implementation on Mac is different but I don't have 
Mac for now. All Mac related condition will be removed in a separated CL once
the Mac part is finished. Since this one is big enough.

[tommycli, 2016/09/21 21:26:16]

Okay that's fine, please add a TODO for yourself explaining that.

[zmin, 2016/09/21 21:52:05]

Done.

+  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);
+  }
+}
+#else
+  UserManager::ShowReauthDialog(browser_context, email_address_,
                                 signin_metrics::Reason::REASON_UNLOCK);
-}
+#endif
 
 void UserManagerScreenHandler::HandleRemoveUser(const base::ListValue* args) {
   DCHECK(args);
   const base::Value* profile_path_value;
   if (!args->Get(0, &profile_path_value)) {
     NOTREACHED();
     return;
   }
 
   base::FilePath profile_path;
@@ skipping 551 matching lines @@
     Profile* profile, Profile::CreateStatus profile_create_status) {
   Browser* browser = chrome::FindAnyBrowser(profile, false);
   if (browser && browser->window()) {
     OnBrowserWindowReady(browser);
   } else {
     registrar_.Add(this,
                    chrome::NOTIFICATION_BROWSER_WINDOW_READY,
                    content::NotificationService::AllSources());
   }
 }