"Lock on idle and suspend": Log out instead if session cannot be locked

chrome/browser/chromeos/login/screen_locker.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/chromeos/login/screen_locker.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
@@ skipping 77 matching lines @@
         break;
       }
 
       default:
         NOTREACHED();
     }
   }
 
   virtual void LockScreen() OVERRIDE {
     VLOG(1) << "Received LockScreen D-Bus signal from session manager";
-    if (session_started_) {
+    if (session_started_ &&
+        chromeos::UserManager::Get()->CanCurrentUserLock()) {

[Nikita (slow), 2013/01/09 12:55:35]

I'm not sure that making logout in this case makes sense for all such cases.

It might be the case for public accounts but not for Guest session.

For Guest session we make sure that we never get here.
But even if we got here it should be a nop not a logout.

       chromeos::ScreenLocker::Show();
     } else {
-      // If the user has not completed the sign in we will log them out. This
-      // avoids complications with displaying the lock screen over the login
-      // screen while remaining secure in the case that they walk away during
-      // the signin steps. See crbug.com/112225 and crbug.com/110933.
+      // If the current user's session cannot be locked or the user has not
+      // completed all sign-in steps yet, log out instead. The latter is done to
+      // avoid complications with displaying the lock screen over the login
+      // screen while remaining secure in the case the user walks away during
+      // the sign-in steps. See crbug.com/112225 and crbug.com/110933.
       VLOG(1) << "Calling session manager's StopSession D-Bus method";
       chromeos::DBusThreadManager::Get()->
           GetSessionManagerClient()->StopSession();
     }
   }
 
   virtual void UnlockScreen() OVERRIDE {
     VLOG(1) << "Received UnlockScreen D-Bus signal from session manager";
     chromeos::ScreenLocker::Hide();
   }
@@ skipping 305 matching lines @@
       content::Details<bool>(&state));
   VLOG(1) << "Calling session manager's HandleLockScreenShown D-Bus method";
   DBusThreadManager::Get()->GetSessionManagerClient()->NotifyLockScreenShown();
 }
 
 content::WebUI* ScreenLocker::GetAssociatedWebUI() {
   return delegate_->GetAssociatedWebUI();
 }
 
 }  // namespace chromeos