Change getAccessToken and getExtensionPrinterAccess to sendWithPromise

chrome/browser/resources/print_preview/cloud_print_interface.js

Index: chrome/browser/resources/print_preview/cloud_print_interface.js
diff --git a/chrome/browser/resources/print_preview/cloud_print_interface.js b/chrome/browser/resources/print_preview/cloud_print_interface.js
index 4c40894b00a7246f83e64d3426ed83593c4883db..9af7d06704d39a5312d8bf5df8860341a24cab32 100644
--- a/chrome/browser/resources/print_preview/cloud_print_interface.js
+++ b/chrome/browser/resources/print_preview/cloud_print_interface.js
@@ -102,13 +102,12 @@ cr.define('cloudprint', function() {
     this.outstandingCloudSearchRequests_ = [];
 
     /**
-     * Event tracker used to keep track of native layer events.
-     * @type {!EventTracker}
-     * @private
+     * Map from authentication types to promises that will be resolved when
+     * the corresponding access token is available.
+     * @private {!Map<string, !Promise>}
      */
-    this.tracker_ = new EventTracker();
+    this.accessTokenRequestMap_ = new Map();

[dpapad, 2017/06/16 22:21:29]

Let's wait for @vitalybuka's response to see if this Map is necessary.

[rbpotter, 2017/06/19 22:19:29]

Done. Removed as it seems the DestinationOrigin.PROFILE feature was
never shipped and has an unclear future.

 
-    this.addEventListeners_();
   }
 
   /**
@@ -340,17 +339,6 @@ cr.define('cloudprint', function() {
           this.onPrinterDone_.bind(this, printerId)));
     },
 
-    /**
-     * Adds event listeners to relevant events.
-     * @private
-     */
-    addEventListeners_: function() {
-      this.tracker_.add(
-          this.nativeLayer_.getEventTarget(),
-          print_preview.NativeLayer.EventType.ACCESS_TOKEN_READY,
-          this.onAccessTokenReady_.bind(this));
-    },
-
     /**
      * Builds request to the Google Cloud Print API.
      * @param {string} method HTTP method of the request.
@@ -430,7 +418,12 @@ cr.define('cloudprint', function() {
         return this.sendRequest_(request);
       } else {
         this.requestQueue_.push(request);
-        this.nativeLayer_.startGetAccessToken(request.origin);
+        if (!this.accessTokenRequestMap_.get(request.origin)) {
+          this.accessTokenRequestMap_.set(
+              request.origin,

[dpapad, 2017/06/16 22:21:29]

Is this a string or a print_preview.DestinationOrigin? Shouldn't the map be
typed as

!Map<!print_preview.DestinationOrigin, !Promise> instead?

[rbpotter, 2017/06/19 22:19:30]

Done.

+              this.nativeLayer_.getAccessToken(request.origin).then(
+                  this.onAccessTokenReady_.bind(this, request.origin)));
+        }
       }
     },
 
@@ -504,20 +497,22 @@ cr.define('cloudprint', function() {
 
     /**
      * Called when a native layer receives access token.
-     * @param {Event} event Contains the authentication type and access token.
+     * @param {!print_preview.DestinationOrigin} authType The authentication
+     *     type.
+     * @param {string} accessToken The access token obtained for |authType|.
      * @private
      */
-    onAccessTokenReady_: function(event) {
+    onAccessTokenReady_: function(authType, accessToken) {
       // TODO(vitalybuka): remove when other Origins implemented.
-      assert(event.authType == print_preview.DestinationOrigin.DEVICE);
+      assert(authType == print_preview.DestinationOrigin.DEVICE);
       this.requestQueue_ = this.requestQueue_.filter(function(request) {
         assert(request.origin == print_preview.DestinationOrigin.DEVICE);
-        if (request.origin != event.authType) {
+        if (request.origin != authType) {
           return true;
         }
-        if (event.accessToken) {
+        if (accessToken) {
           request.xhr.setRequestHeader('Authorization',
-                                       'Bearer ' + event.accessToken);
+                                       'Bearer ' + accessToken);
           this.sendRequest_(request);
         } else {  // No valid token.
           // Without abort status does not exist.
@@ -526,6 +521,7 @@ cr.define('cloudprint', function() {
         }
         return false;
       }, this);
+      this.accessTokenRequestMap_.delete(authType);
     },
 
     /**