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 151 matching lines @@
 
     /**
      * Local destinations are CROS destinations on ChromeOS because they require
      * extra setup.
      * @private {!print_preview.DestinationOrigin}
      */
     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}

[dpapad, 2017/06/19 17:43:37]

Nit: @private {boolean}

[rbpotter, 2017/06/19 23:10:49]

Done.

+     * @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 412 matching lines @@
           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 1034 matching lines @@
       return this.getDestinationKey_(
           destination.origin, destination.id, destination.account);
     }
   };
 
   // Export
   return {
     DestinationStore: DestinationStore
   };
 });