Fix bug with login-prompt-visible not being sent in some rare cases.

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

 // Copyright (c) 2012 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/chromeos/login/signin_screen_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/cancelable_callback.h"
@@ skipping 991 matching lines @@
   }
 
   base::FundamentalValue animated_value(animated);
   base::FundamentalValue guest_value(delegate_->IsShowGuest());
   web_ui()->CallJavascriptFunction("login.AccountPickerScreen.loadUsers",
                                    users_list, animated_value, guest_value);
 }
 
 void SigninScreenHandler::HandleAccountPickerReady(
     const base::ListValue* args) {
+  LOG(INFO) << "Login WebUI >> AccountPickerReady";
 
   PrefService* prefs = g_browser_process->local_state();
   if (prefs->GetBoolean(prefs::kFactoryResetRequested)) {
     prefs->SetBoolean(prefs::kFactoryResetRequested, false);
     prefs->CommitPendingWrite();
     base::ListValue args;
     HandleToggleResetScreen(&args);
     return;
   }
 
@@ skipping 110 matching lines @@
 void SigninScreenHandler::HandleCreateAccount(const base::ListValue* args) {
   if (delegate_)
     delegate_->CreateAccount();
 }
 
 void SigninScreenHandler::HandleOpenProxySettings(const base::ListValue* args) {
   BaseLoginDisplayHost::default_host()->OpenProxySettings();
 }
 
 void SigninScreenHandler::HandleLoginVisible(const base::ListValue* args) {
-  LOG(INFO) << "Login WebUI >> LoginVisible, webui_visible_: "
-            << webui_visible_;
+  std::string source;
+  if (!args->GetString(0, &source)) {
+    NOTREACHED();
+    return;
+  }
+
+  LOG(INFO) << "Login WebUI >> LoginVisible, source: " << source
+            << ", webui_visible_: " << webui_visible_;
   if (!webui_visible_) {
     // There might be multiple messages from OOBE UI so send notifications after
     // the first one only.
     content::NotificationService::current()->Notify(
         chrome::NOTIFICATION_LOGIN_WEBUI_VISIBLE,
         content::NotificationService::AllSources(),
         content::NotificationService::NoDetails());
   }
   webui_visible_ = true;
   if (ScreenLocker::default_screen_locker())
@@ skipping 60 matching lines @@
   }
   for (UserList::const_iterator it = users.begin(); it != users.end(); ++it) {
     if (!cros_settings->FindEmailInList(kAccountsPrefUsers, (*it)->email())) {
       return false;
     }
   }
   return true;
 }
 
 }  // namespace chromeos