Change getExtensionPrinters to cr.sendWithPromise

chrome/browser/resources/print_preview/native_layer.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.exportPath('print_preview');
 
 /**
  * @typedef {{selectSaveAsPdfDestination: boolean,
  *            layoutSettings.portrait: boolean,
  *            pageRange: string,
@@ skipping 55 matching lines @@
         this.onDidGetDefaultPageLayout_.bind(this);
     global.onDidGetPreviewPageCount =
         this.onDidGetPreviewPageCount_.bind(this);
     global.onDidPreviewPage = this.onDidPreviewPage_.bind(this);
     global.updatePrintPreview = this.onUpdatePrintPreview_.bind(this);
     global.onDidGetAccessToken = this.onDidGetAccessToken_.bind(this);
     global.onPrivetPrinterChanged = this.onPrivetPrinterChanged_.bind(this);
     global.onPrivetCapabilitiesSet =
         this.onPrivetCapabilitiesSet_.bind(this);
     global.onPrivetPrintFailed = this.onPrivetPrintFailed_.bind(this);
-    global.onExtensionPrintersAdded =
-        this.onExtensionPrintersAdded_.bind(this);
     global.onExtensionCapabilitiesSet =
         this.onExtensionCapabilitiesSet_.bind(this);
     global.onEnableManipulateSettingsForTest =
         this.onEnableManipulateSettingsForTest_.bind(this);
     global.printPresetOptionsFromDocument =
         this.onPrintPresetOptionsFromDocument_.bind(this);
     global.onProvisionalPrinterResolved =
         this.onProvisionalDestinationResolved_.bind(this);
     global.failedToResolveProvisionalPrinter =
         this.failedToResolveProvisionalDestination_.bind(this);
@@ skipping 47 matching lines @@
     PREVIEW_GENERATION_DONE:
         'print_preview.NativeLayer.PREVIEW_GENERATION_DONE',
     PREVIEW_GENERATION_FAIL:
         'print_preview.NativeLayer.PREVIEW_GENERATION_FAIL',
     PRINT_TO_CLOUD: 'print_preview.NativeLayer.PRINT_TO_CLOUD',
     SETTINGS_INVALID: 'print_preview.NativeLayer.SETTINGS_INVALID',
     PRIVET_PRINTER_CHANGED: 'print_preview.NativeLayer.PRIVET_PRINTER_CHANGED',
     PRIVET_CAPABILITIES_SET:
         'print_preview.NativeLayer.PRIVET_CAPABILITIES_SET',
     PRIVET_PRINT_FAILED: 'print_preview.NativeLayer.PRIVET_PRINT_FAILED',
-    EXTENSION_PRINTERS_ADDED:
-        'print_preview.NativeLayer.EXTENSION_PRINTERS_ADDED',
     EXTENSION_CAPABILITIES_SET:
         'print_preview.NativeLayer.EXTENSION_CAPABILITIES_SET',
     PRINT_PRESET_OPTIONS: 'print_preview.NativeLayer.PRINT_PRESET_OPTIONS',
     PROVISIONAL_DESTINATION_RESOLVED:
         'print_preview.NativeLayer.PROVISIONAL_DESTINATION_RESOLVED'
   };
 
   /**
    * Constant values matching printing::DuplexMode enum.
    * @enum {number}
@@ skipping 99 matching lines @@
     /**
      * Requests the privet destination's printing capabilities. A
      * PRIVET_CAPABILITIES_SET event will be dispatched in response.
      * @param {string} destinationId ID of the destination.
      */
     startGetPrivetDestinationCapabilities: function(destinationId) {
       chrome.send('getPrivetPrinterCapabilities', [destinationId]);
     },
 
     /**
      * Requests that extension system dispatches an event requesting the list of

[dpapad, 2017/06/07 18:21:39]

This comment sounds too indirect (requesting a request to be sent). Can we
simplify as follows?

Request a list of extension printers. Printers are reported as they are found by
a series of 'extension-printers-added' events.

[rbpotter, 2017/06/07 19:14:12]

Done.

      * extension managed printers.
+     * @return {!Promise} Will be resolved when all extension managed printers
+     *     have been sent.
      */
-    startGetExtensionDestinations: function() {
-      chrome.send('getExtensionPrinters');
+    getExtensionPrinters: function() {
+      return cr.sendWithPromise('getExtensionPrinters');
     },
 
     /**
      * Requests an extension destination's printing capabilities. A
      * EXTENSION_CAPABILITIES_SET event will be dispatched in response.
      * @param {string} destinationId The ID of the destination whose
      *     capabilities are requested.
      */
     startGetExtensionDestinationCapabilities: function(destinationId) {
       chrome.send('getExtensionPrinterCapabilities', [destinationId]);
@@ skipping 534 matching lines @@
      * @private
      */
     onPrivetPrintFailed_: function(http_error) {
       var privetPrintFailedEvent =
             new Event(NativeLayer.EventType.PRIVET_PRINT_FAILED);
       privetPrintFailedEvent.httpError = http_error;
       this.eventTarget_.dispatchEvent(privetPrintFailedEvent);
     },
 
     /**
-     * @param {Array<!{extensionId: string,
-     *                 extensionName: string,
-     *                 id: string,
-     *                 name: string,
-     *                 description: (string|undefined),
-     *                 provisional: (boolean|undefined)}>} printers The list
-     *     containing information about printers added by an extension.
-     * @param {boolean} done Whether this is the final list of extension
-     *     managed printers.
-     */
-    onExtensionPrintersAdded_: function(printers, done) {
-      var event = new Event(NativeLayer.EventType.EXTENSION_PRINTERS_ADDED);
-      event.printers = printers;
-      event.done = done;
-      this.eventTarget_.dispatchEvent(event);
-    },
-
-    /**
      * Called when an extension responds to a request for an extension printer
      * capabilities.
      * @param {string} printerId The printer's ID.
      * @param {!Object} capabilities The reported printer capabilities.
      */
     onExtensionCapabilitiesSet_: function(printerId,
                                           capabilities) {
       var event = new Event(NativeLayer.EventType.EXTENSION_CAPABILITIES_SET);
       event.printerId = printerId;
       event.capabilities = capabilities;
@@ skipping 261 matching lines @@
       return this.serializedDefaultDestinationSelectionRulesStr_;
     }
   };
 
   // Export
   return {
     NativeInitialSettings: NativeInitialSettings,
     NativeLayer: NativeLayer
   };
 });