Fix Launcher crash in ChromeOS guest mode.

chrome/browser/ui/app_list/app_list_view_delegate.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/app_list/app_list_view_delegate.h"
 
 #include <vector>
 
 #include "apps/custom_launcher_page_contents.h"
 #include "base/callback.h"
@@ skipping 267 matching lines @@
   if (!profile_) {
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/431326 is fixed.
     tracked_objects::ScopedTracker tracking_profile2(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "431326 AppListViewDelegate::SetProfile2"));
 
     speech_ui_->SetSpeechRecognitionState(app_list::SPEECH_RECOGNITION_OFF);
     return;
   }
 
+  // If we are in guest mode, the new profile should be an incognito profile.
+  // Otherwise, this may later hit a check (same condition as this one) in
+  // Browser::Browser when opening links in a browser window (see
+  // http://crbug.com/460437).
+  DCHECK(!profile_->IsGuestSession() || profile_->IsOffTheRecord())
+      << "Guest mode must use incognito profile";
+
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/431326 is fixed.
   tracked_objects::ScopedTracker tracking_profile3(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "431326 AppListViewDelegate::SetProfile3"));
   template_url_service_observer_.RemoveAll();
   if (app_list::switches::IsExperimentalAppListEnabled()) {
     TemplateURLService* template_url_service =
         TemplateURLServiceFactory::GetForProfile(profile_);
     template_url_service_observer_.Add(template_url_service);
   }
@@ skipping 528 matching lines @@
 
       // SigninManagerFactory is not a leaky singleton (unlike this class), and
       // its destructor will check that it has no remaining observers.
       scoped_observer_.RemoveAll();
       SigninManagerFactory::GetInstance()->RemoveObserver(this);
       break;
     default:
       NOTREACHED();
   }
 }