Change getExtensionPrinters to cr.sendWithPromise

chrome/browser/resources/print_preview/data/destination_store.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.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * A data store that stores destinations and dispatches events when the data
    * store changes.
@@ skipping 1092 matching lines @@
 
     /** Initializes loading of extension managed print destinations. */
     startLoadExtensionDestinations: function() {
       if (this.hasLoadedAllExtensionDestinations_)
         return;
 
       if (this.isExtensionDestinationSearchInProgress_)
         clearTimeout(this.extensionSearchTimeout_);
 
       this.isExtensionDestinationSearchInProgress_ = true;
-      this.nativeLayer_.startGetExtensionDestinations();
+
+      cr.addWebUIListener('extension-printers-added',
+          this.onExtensionPrintersAdded_.bind(this));
+      this.nativeLayer_.getExtensionPrinters().then(
+          this.onExtensionPrintersDone_.bind(this));
       cr.dispatchSimpleEvent(
           this, DestinationStore.EventType.DESTINATION_SEARCH_STARTED);
       this.extensionSearchTimeout_ = setTimeout(
           this.endExtensionPrinterSearch_.bind(this),
           DestinationStore.EXTENSION_SEARCH_DURATION_);
     },
 
     /**
      * Initiates loading of cloud destinations.
      * @param {print_preview.DestinationOrigin=} opt_origin Search destinations
@@ skipping 252 matching lines @@
       this.tracker_.add(
           nativeLayerEventTarget,
           print_preview.NativeLayer.EventType.PRIVET_PRINTER_CHANGED,
           this.onPrivetPrinterAdded_.bind(this));
       this.tracker_.add(
           nativeLayerEventTarget,
           print_preview.NativeLayer.EventType.PRIVET_CAPABILITIES_SET,
           this.onPrivetCapabilitiesSet_.bind(this));
       this.tracker_.add(
           nativeLayerEventTarget,
-          print_preview.NativeLayer.EventType.EXTENSION_PRINTERS_ADDED,
-          this.onExtensionPrintersAdded_.bind(this));
-      this.tracker_.add(
-          nativeLayerEventTarget,
           print_preview.NativeLayer.EventType.EXTENSION_CAPABILITIES_SET,
           this.onExtensionCapabilitiesSet_.bind(this));
       this.tracker_.add(
           nativeLayerEventTarget,
           print_preview.NativeLayer.EventType.PROVISIONAL_DESTINATION_RESOLVED,
           this.handleProvisionalDestinationResolved_.bind(this));
     },
 
     /**
      * Creates a local PDF print destination.
@@ skipping 218 matching lines @@
           print_preview.PrivetDestinationParser.parse(event.printer);
       destinations.forEach(function(dest) {
         dest.capabilities = event.capabilities;
         this.updateDestination_(dest);
       }, this);
     },
 
     /**
      * Called when an extension responds to a getExtensionDestinations
      * request.
-     * @param {Object} event Contains information about list of printers
-     *     reported by the extension.
-     *     {@code done} parameter is set iff this is the final list of printers
-     *     returned as part of getExtensionDestinations request.
+     * @param {Array<!{extensionId: string,

[dpapad, 2017/06/03 01:00:00]

!Array

It does not seem that the function expects a null input, otherwise the call to
map() would throw an error.

[rbpotter, 2017/06/03 01:52:39]

Done.

+     *                 extensionName: string,
+     *                 id: string,
+     *                 name: string,
+     *                 description: (string|undefined),
+     *                 provisional: (boolean|undefined)}>} printers The list
+     *     containing information about printers added by an extension.
      * @private
      */
-    onExtensionPrintersAdded_: function(event) {
-      this.insertDestinations_(event.printers.map(function(printer) {
+    onExtensionPrintersAdded_: function(printers) {
+      this.insertDestinations_(printers.map(function(printer) {

[dpapad, 2017/06/03 01:00:00]

Nit: I think this is equivalent to the shorter

this.insertDestinations_(
    printers.map(print_preview.ExtensionDestinationParser.parse));

[rbpotter, 2017/06/03 01:52:40]

Done.

         return print_preview.ExtensionDestinationParser.parse(printer);
       }));
+    },
 
-      if (event.done && this.isExtensionDestinationSearchInProgress_) {
+    /**
+     * Called when all extensions are done adding printers.
+     * @param {boolean} done Whether printers are done
+     * @private
+     */
+    onExtensionPrintersDone_: function(done) {
+      if (done && this.isExtensionDestinationSearchInProgress_) {
         clearTimeout(this.extensionSearchTimeout_);
         this.endExtensionPrinterSearch_();
       }
     },
 
     /**
      * Called when capabilities for an extension managed printer are set.
      * @param {Object} event Contains the printer's capabilities and ID.
      * @private
      */
@@ skipping 45 matching lines @@
       return this.getDestinationKey_(
           destination.origin, destination.id, destination.account);
     }
   };
 
   // Export
   return {
     DestinationStore: DestinationStore
   };
 });