Add policy to use system default printer

chrome/browser/resources/print_preview/data/destination_store.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.define('print_preview', function() {
   'use strict';
 
   /**
    * A data store that stores destinations and dispatches events when the data
    * store changes.
@@ skipping 182 matching lines @@
     /**
      * Local destinations are CROS destinations on ChromeOS because they require
      * extra setup.
      * @type {!print_preview.DestinationOrigin}
      * @private
      */
     this.platformOrigin_ = cr.isChromeOS ?
         print_preview.DestinationOrigin.CROS :
         print_preview.DestinationOrigin.LOCAL;
 
+    /**
+     * Whether to default to the system default printer instead of the most
+     * recent destination.
+     * @type {boolean}
+     * @private
+     */
+    this.useSystemDefaultAsDefault_ =
+        loadTimeData.getBoolean('useSystemDefaultPrinter');
+
     this.addEventListeners_();
     this.reset_();
   }
 
   /**
    * Event types dispatched by the data store.
    * @enum {string}
    */
   DestinationStore.EventType = {
     DESTINATION_SEARCH_DONE:
@@ skipping 399 matching lines @@
       }
 
       var origin = null;
       var id = '';
       var account = '';
       var name = '';
       var capabilities = null;
       var extensionId = '';
       var extensionName = '';
       var foundDestination = false;
       if (this.appState_.recentDestinations) {

[skau, 2017/06/15 19:41:31]

Can !this.useSystemDefaultAsDefault_ be moved here?  it looks like
foundDestination only changes on 654 and 656.  There are also no side effects of
this code block if a destination is not found.

[rbpotter, 2017/06/16 02:21:46]

Think we still want to mark the recent destinations recent, so that they
populate the "Recent Destinations" list. This happens on line 653.

         // Run through the destinations forward. As soon as we find a
         // destination, don't select any future destinations, just mark
         // them recent. Otherwise, there is a race condition between selecting
         // destinations/updating the print ticket and this selecting a new
         // destination that causes random print preview errors.
         for (var i = 0; i < this.appState_.recentDestinations.length; i++) {
           origin = this.appState_.recentDestinations[i].origin;
           id = this.appState_.recentDestinations[i].id;
           account = this.appState_.recentDestinations[i].account || '';
           name = this.appState_.recentDestinations[i].name || '';
           capabilities = this.appState_.recentDestinations[i].capabilities;
           extensionId = this.appState_.recentDestinations[i].extensionId ||
                         '';
           extensionName =
               this.appState_.recentDestinations[i].extensionName || '';
           var candidate =
               this.destinationMap_[this.getDestinationKey_(origin,
                                                            id, account)];
           if (candidate != null) {
-            if (!foundDestination)
+            if (!foundDestination && !this.useSystemDefaultAsDefault_)
               this.selectDestination(candidate);
             candidate.isRecent = true;
             foundDestination = true;
-          } else if (!foundDestination) {
+          } else if (!foundDestination && !this.useSystemDefaultAsDefault_) {
             foundDestination = this.fetchPreselectedDestination_(
                                     origin,
                                     id,
                                     account,
                                     name,
                                     capabilities,
                                     extensionId,
                                     extensionName);
           }
         }
       }
-      if (foundDestination) return;
+      if (foundDestination && !this.useSystemDefaultAsDefault_) return;
 
       // Try the system default
       id = this.systemDefaultDestinationId_ || '';
       origin = id == print_preview.Destination.GooglePromotedId.SAVE_AS_PDF ?
           print_preview.DestinationOrigin.LOCAL :
           this.platformOrigin_;
       account = '';
       var candidate =
           this.destinationMap_[this.getDestinationKey_(origin, id, account)];
       if (candidate != null) {
@@ skipping 1026 matching lines @@
       return this.getDestinationKey_(
           destination.origin, destination.id, destination.account);
     }
   };
 
   // Export
   return {
     DestinationStore: DestinationStore
   };
 });