Prevent new Browser windows from violating the IncognitoModeAvailability policy.

chrome/browser/ui/browser.cc

 // Copyright 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/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // defined(OS_WIN)
@@ skipping 327 matching lines @@
       weak_factory_(this),
       content_setting_bubble_model_delegate_(
           new BrowserContentSettingBubbleModelDelegate(this)),
       toolbar_model_delegate_(new BrowserToolbarModelDelegate(this)),
       tab_restore_service_delegate_(new BrowserTabRestoreServiceDelegate(this)),
       synced_window_delegate_(new BrowserSyncedWindowDelegate(this)),
       bookmark_bar_state_(BookmarkBar::HIDDEN),
       command_controller_(new chrome::BrowserCommandController(
           this, g_browser_process->profile_manager())),
       window_has_shown_(false) {
+  // If this causes a crash then a window is being opened using a profile type
+  // that is disallowed by policy. The crash prevents the disabled window type
+  // from opening at all, but the path that triggered it should be fixed.
+  CHECK(IncognitoModePrefs::CanOpenBrowser(profile_));
+
   if (!app_name_.empty())
     chrome::RegisterAppPrefs(app_name_, profile_);
   tab_strip_model_->AddObserver(this);
 
   toolbar_model_.reset(new ToolbarModelImpl(toolbar_model_delegate_.get()));
   search_model_.reset(new SearchModel());
   search_delegate_.reset(
       new SearchDelegate(search_model_.get(), toolbar_model_.get()));
 
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
@@ skipping 1852 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }