Allow partial update for notification update API

chrome/renderer/resources/extensions/notifications_custom_bindings.js

 // Copyright 2013 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 notifications API.
 var binding = require('binding').Binding.create('notifications');
 
 var sendRequest = require('sendRequest').sendRequest;
 var imageUtil = require('imageUtil');
 var lastError = require('lastError');
 
 function image_data_setter(context, key) {
   var f = function(val) {
     this[key] = val;
   };
   return $Function.bind(f, context);
 }
 
 function replaceNotificationOptionURLs(notification_details, callback) {
   // A URL Spec is an object with the following keys:
   //  path: The resource to be downloaded.
   //  width: (optional) The maximum width of the image to be downloaded.
   //  height: (optional) The maximum height of the image to be downloaded.
   //  callback: A function to be called when the URL is complete. It
   //    should accept an ImageData object and set the appropriate
   //    field in the output of create.
 
   // TODO(dewittj): Try to remove hard-coding of image sizes.
-  // |iconUrl| is required.
-  var url_specs = [{
-    path: notification_details.iconUrl,
-    width: 80,
-    height: 80,
-    callback: image_data_setter(notification_details, 'iconBitmap')
-  }];
+  // |iconUrl| might be optional for notification updates.
+  var url_specs = [];
+  if (notification_details.iconUrl) {
+    $Array.push(url_specs, {
+      path: notification_details.iconUrl,
+      width: 80,
+      height: 80,
+      callback: image_data_setter(notification_details, 'iconBitmap')
+    });
+  }
 
   // |imageUrl| is optional.
   if (notification_details.imageUrl) {
     $Array.push(url_specs, {
       path: notification_details.imageUrl,
       width: 360,
       height: 540,
       callback: image_data_setter(notification_details, 'imageBitmap')
     });
   }
 
   // Each button has an optional icon.
   var button_list = notification_details.buttons;
   if (button_list && typeof button_list.length === 'number') {
     var num_buttons = button_list.length;
     for (var i = 0; i < num_buttons; i++) {
       if (button_list[i].iconUrl) {
         $Array.push(url_specs, {
           path: button_list[i].iconUrl,
           width: 16,
           height: 16,
           callback: image_data_setter(button_list[i], 'iconBitmap')
         });
       }
     }
   }
 
+  if (!url_specs.length) {
+    callback(true);
+    return;
+  }
+
   var errors = 0;
 
   imageUtil.loadAllImages(url_specs, {
     onerror: function(index) {
       errors++;
     },
     oncomplete: function(imageData) {
       if (errors > 0) {
         callback(false);
         return;
@@ skipping 36 matching lines @@
 
 var notificationsCustomHook = function(bindingsAPI, extensionId) {
   var apiFunctions = bindingsAPI.apiFunctions;
   apiFunctions.setHandleRequest('create', handleCreate);
   apiFunctions.setHandleRequest('update', handleUpdate);
 };
 
 binding.registerCustomHook(notificationsCustomHook);
 
 exports.binding = binding.generate();