Change getExtensionPrinters to cr.sendWithPromise

chrome/browser/resources/print_preview/native_layer.js

Index: chrome/browser/resources/print_preview/native_layer.js
diff --git a/chrome/browser/resources/print_preview/native_layer.js b/chrome/browser/resources/print_preview/native_layer.js
index 4ad76dea1179c79c459e089a01e900fc107a49e3..8e7c0b115943f0aa69076e7f55229a970d437276 100644
--- a/chrome/browser/resources/print_preview/native_layer.js
+++ b/chrome/browser/resources/print_preview/native_layer.js
@@ -73,8 +73,6 @@ cr.define('print_preview', function() {
     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 =
@@ -142,8 +140,6 @@ cr.define('print_preview', function() {
     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',
@@ -265,9 +261,11 @@ cr.define('print_preview', function() {
     /**
      * 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');
     },
 
     /**
@@ -821,24 +819,6 @@ cr.define('print_preview', function() {
       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.