Allow settings dialog to be opened via the app launcher, as a packaged app.

chrome/renderer/resources/extensions/app_window_custom_bindings.js

 // 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.
 
 // Custom bindings for the app_window API.
 
 var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
 var sendRequest = require('sendRequest').sendRequest;
 var appWindowNatives = requireNative('app_window');
 var forEach = require('utils').forEach;
 var GetView = appWindowNatives.GetView;
 
 chromeHidden.registerCustomHook('app.window', function(bindingsAPI) {
   var apiFunctions = bindingsAPI.apiFunctions;
   apiFunctions.setCustomCallback('create',
                                  function(name, request, windowParams) {
-    if (!windowParams.viewId) {
-      // Create failed? If given a callback, trigger it with an undefined
-      // object.
+    var view = null;
+    if (windowParams.viewId)
+      view = GetView(windowParams.viewId, windowParams.injectTitlebar);
+
+    if (!view) {
+      // No route to created window. If given a callback, trigger it with an
+      // undefined object.
       if (request.callback) {
         request.callback()
         delete request.callback;
       }
       return;
     }
 
-    var view = GetView(windowParams.viewId, windowParams.injectTitlebar);
-
     // Initialize appWindowData in the newly created JS context
     view.chrome.app.window.initializeAppWindow(windowParams);
 
     if (request.callback) {
       request.callback(view.chrome.app.window.current());
       delete request.callback;
     }
   });
 
   apiFunctions.setHandleRequest('current', function() {
@@ skipping 20 matching lines @@
     Object.defineProperty(AppWindow.prototype, 'id', {get: function() {
       return chromeHidden.appWindowData.id;
     }});
 
     chromeHidden.appWindowData = {
       id: params.id || ''
     };
     chromeHidden.currentAppWindow = new AppWindow;
   });
 });