Print an error when trying to launch an incognito browser and incognito is disabled.

chrome/browser/ui/browser_init.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/ui/browser_init.h"
 
 #include <algorithm>   // For max().
 
 #include "base/compiler_specific.h"
 #include "base/environment.h"
@@ skipping 531 matching lines @@
     chromeos::CrosLibrary::Get()->GetNetworkLibrary()
         ->AddNetworkManagerObserver(
             chromeos::NetworkStateNotifier::GetInstance());
   }
 #endif
 
   // Continue with the incognito profile from here on if Incognito mode
   // is forced.
   if (IncognitoIsForced(command_line, profile->GetPrefs())) {
     profile = profile->GetOffTheRecordProfile();
+  } else if (command_line.HasSwitch(switches::kIncognito)) {
+    LOG(WARNING) << "Incognito mode disabled by policy, launching a normal "
+                 << "browser session.";
   }
 
   BrowserInit::LaunchWithProfile lwp(cur_dir, command_line, this);
   std::vector<GURL> urls_to_launch = BrowserInit::GetURLsFromCommandLine(
       command_line, cur_dir, profile);
   bool launched = lwp.Launch(profile, urls_to_launch, process_startup);
   in_startup = false;
 
   if (!launched) {
     LOG(ERROR) << "launch error";
@@ skipping 887 matching lines @@
     return false;
   automation->SetExpectedTabCount(expected_tabs);
 
   AutomationProviderList* list =
       g_browser_process->InitAutomationProviderList();
   DCHECK(list);
   list->AddProvider(automation);
 
   return true;
 }