Re-use PromiseResolver helper in print preview.

chrome/browser/resources/print_preview/search/provisional_destination_resolver.js

 // Copyright 2015 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';
 
   /** @enum {string} */
   var ResolverState = {
     INITIAL: 'INITIAL',
     ACTIVE: 'ACTIVE',
     GRANTING_PERMISSION: 'GRANTING_PERMISSION',
     ERROR: 'ERROR',
     DONE: 'DONE'
   };
 
   /**
-   * Utility class for bundling a promise object with it's resolver methods.
-   * @param {!Promise<!print_preview.Destination>} promise A promise returning
-   *     a destination.
-   * @param {function(!print_preview.Destination)} resolve Function resolving
-   *     the promise.
-   * @param {function()} reject Function for rejecting the promise.
-   * @constructor @struct
-   */
-  function PromiseResolver(promise, resolve, reject) {

[Dan Beam, 2016/03/03 21:18:24]

nit: perhaps we should templatize PromiseResolver

[dpapad, 2016/03/04 18:58:42]

Done. I templatized it in a bit simpler way compared to
https://github.com/google/closure-library/blob/master/closure/goog/promise/re....
I was not sure why Closure's Resolver is annotated in a more complicated way. We
can update the type annotations to match those, if needed in the future.

-    /** @type {!Promise<!print_preview.Destination>} */
-    this.promise = promise;
-    /** @type {function(!print_preview.Destination)} */
-    this.resolve = resolve;
-    /** @type {function()} */
-    this.reject = reject;
-  }
-
-  /**
-   * Create a Promise and an associated PromiseResolver.
-   * @return {!PromiseResolver}
-   */
-  PromiseResolver.create = function() {
-    var reject = null;
-    var resolve = null;
-    /** @type {!Promise<!print_preview.Destination>} */
-    var promise = new Promise(function(resolvePromise, rejectPromise) {
-      resolve = /** @type {function(!print_preview.Destination)}*/(
-          resolvePromise);
-      reject = /** @type {function()} */(rejectPromise);
-    });
-
-    return new PromiseResolver(promise, resolve, reject);
-  };
-
-  /**
    * Overlay used to resolve a provisional extension destination. The user is
    * prompted to allow print preview to grant a USB device access to an
    * extension associated with the destination. If user agrees destination
    * resolvement is attempted (which includes granting the extension USB access
    * and requesting destination description from the extension). The overlay is
    * hidden when destination resolving is done.
    *
    * @param {!print_preview.DestinationStore} destinationStore The destination
    *    store containing the destination. Used as a proxy to native layer for
    *    resolving the destination.
@@ skipping 56 matching lines @@
           this.onDestinationResolved_.bind(this));
     },
 
     /** @override */
     onSetVisibleInternal: function(visible) {
       if (visible) {
         assert(this.state_ == ResolverState.INITIAL,
                'Showing overlay while not in initial state.');
         assert(!this.promiseResolver_, 'Promise resolver already set.');
         this.setState_(ResolverState.ACTIVE);
-        this.promiseResolver_ = PromiseResolver.create();
+        this.promiseResolver_ = new PromiseResolver();
         this.getChildElement('.default').focus();
       } else if (this.state_ != ResolverState.DONE) {
         assert(this.state_ != ResolverState.INITIAL, 'Hiding in initial state');
         this.setState_(ResolverState.DONE);
         this.promiseResolver_.reject();
         this.promiseResolver_ = null;
       }
     },
 
     /** @override */
@@ skipping 103 matching lines @@
 
       assert(this.promiseResolver_, 'Promise resolver not created.');
       return this.promiseResolver_.promise;
     }
   };
 
   return {
     ProvisionalDestinationResolver: ProvisionalDestinationResolver
   };
 });