Print Preview: Make useCloudPrint a WebUI event

chrome/browser/resources/print_preview/print_preview.js

Index: chrome/browser/resources/print_preview/print_preview.js
diff --git a/chrome/browser/resources/print_preview/print_preview.js b/chrome/browser/resources/print_preview/print_preview.js
index 741a50e1d1d08eb1df0cd7cd992dc8f4a83254f7..1b6bd406775667cc552ab4309c701ed7fab17bfa 100644
--- a/chrome/browser/resources/print_preview/print_preview.js
+++ b/chrome/browser/resources/print_preview/print_preview.js
@@ -340,16 +340,14 @@ cr.define('print_preview', function() {
           'extension-printers-added',
           this.destinationStore_.onExtensionPrintersAdded_.bind(
               this.destinationStore_));
+      this.listenerTracker.add(
+          'use-cloud-print', this.onCloudPrintEnable_.bind(this));
     },
 
     /** @override */
     enterDocument: function() {
       // Native layer events.
       var nativeLayerEventTarget = this.nativeLayer_.getEventTarget();
-      this.tracker.add(
-          nativeLayerEventTarget,
-          print_preview.NativeLayer.EventType.CLOUD_PRINT_ENABLE,
-          this.onCloudPrintEnable_.bind(this));
       this.tracker.add(
           nativeLayerEventTarget,
           print_preview.NativeLayer.EventType.SETTINGS_INVALID,
@@ -688,16 +686,17 @@ cr.define('print_preview', function() {
     },
 
     /**
-     * Calls when the native layer enables Google Cloud Print integration.
+     * Called when Google Cloud Print integration is enabled by the
+     * PrintPreviewHandler.
      * Fetches the user's cloud printers.
-     * @param {Event} event Contains the base URL of the Google Cloud Print
-     *     service.
+     * @param {string} cloudPrintUrl The URL to use for cloud print servers.
+     * @param {boolean} appKioskMode Whether to print automatically for kiosk
+     *     mode.
      * @private
      */
-    onCloudPrintEnable_: function(event) {
+    onCloudPrintEnable_: function(cloudPrintUrl, appKioskMode) {
       this.cloudPrintInterface_ = new cloudprint.CloudPrintInterface(
-          event.baseCloudPrintUrl, this.nativeLayer_, this.userInfo_,
-          event.appKioskMode);
+          cloudPrintUrl, this.nativeLayer_, this.userInfo_, appKioskMode);

[rbpotter, 2017/06/27 22:30:30]

Note: there is now no reason cloudPrintUrl or appKioskMode should ever
be undefined.

       this.tracker.add(
           this.cloudPrintInterface_,
           cloudprint.CloudPrintInterfaceEventType.SUBMIT_DONE,