Remove lock screen item from menu and disable screen lock on guest session.

chrome/browser/chromeos/login/screen_locker.cc

 // Copyright (c) 2011 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/chromeos/login/screen_locker.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 329 matching lines @@
   delegate_->ShowErrorMessage(message, sign_out_only);
 }
 
 void ScreenLocker::SetLoginStatusConsumer(
     chromeos::LoginStatusConsumer* consumer) {
   login_status_consumer_ = consumer;
 }
 
 // static
 void ScreenLocker::Show() {
-  VLOG(1) << "In ScreenLocker::Show";
+  DVLOG(1) << "In ScreenLocker::Show";
   UserMetrics::RecordAction(UserMetricsAction("ScreenLocker_Show"));
   DCHECK(MessageLoop::current()->type() == MessageLoop::TYPE_UI);
 
+  // Check whether the currently logged in user is a guest account and if so,
+  // refuse to lock the screen (crosbug.com/23764).
+  // TODO(flackr): We can allow lock screen for guest accounts when
+  // unlock_on_input is supported by the WebUI screen locker.
+  if (UserManager::Get()->logged_in_user().email().empty()) {
+    DVLOG(1) << "Show: Refusing to lock screen for guest account.";
+    return;
+  }
+
   // Exit fullscreen.
   Browser* browser = BrowserList::GetLastActive();
   // browser can be NULL if we receive a lock request before the first browser
   // window is shown.
   if (browser && browser->window()->IsFullscreen()) {
     browser->ToggleFullscreenMode(false);
   }
 
   if (!screen_locker_) {
-    VLOG(1) << "Show: Locking screen";
+    DVLOG(1) << "Show: Locking screen";
     ScreenLocker* locker =
         new ScreenLocker(UserManager::Get()->logged_in_user());
     locker->Init();
   } else {
     // PowerManager re-sends lock screen signal if it doesn't
     // receive the response within timeout. Just send complete
     // signal.
-    VLOG(1) << "Show: locker already exists. Just sending completion event.";
+    DVLOG(1) << "Show: locker already exists. Just sending completion event.";
     CrosLibrary::Get()->GetScreenLockLibrary()->NotifyScreenLockCompleted();
   }
 }
 
 // static
 void ScreenLocker::Hide() {
   DCHECK(MessageLoop::current()->type() == MessageLoop::TYPE_UI);
   DCHECK(screen_locker_);
   VLOG(1) << "Hide: Deleting ScreenLocker: " << screen_locker_;
   MessageLoopForUI::current()->DeleteSoon(FROM_HERE, screen_locker_);
@@ skipping 59 matching lines @@
 
   bool state = true;
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_SCREEN_LOCK_STATE_CHANGED,
       content::Source<ScreenLocker>(this),
       content::Details<bool>(&state));
   CrosLibrary::Get()->GetScreenLockLibrary()->NotifyScreenLockCompleted();
 }
 
 }  // namespace chromeos