Set orientation to 'AUTO' if we hide orientation option from user.

chrome/browser/resources/print_preview/data/print_ticket_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';
 
   // TODO(rltoscano): Maybe clear print ticket when destination changes. Or
   // better yet, carry over any print ticket state that is possible. I.e. if
   // destination changes, the new destination might not support duplex anymore,
@@ skipping 402 matching lines @@
       }
       if (this.mediaSize.isCapabilityAvailable()) {
         var value = this.mediaSize.getValue();
         cjt.print.media_size = {
           width_microns: value.width_microns,
           height_microns: value.height_microns,
           is_continuous_feed: value.is_continuous_feed,
           vendor_id: value.vendor_id
         };
       }
-      if (this.landscape.isCapabilityAvailable() &&
-          this.landscape.isUserEdited()) {
+      if (!this.landscape.isCapabilityAvailable()) {
+        // In this case "orientation" option is hidden from user, so user can't
+        // adjust it for page content, see Landscape.isCapabilityAvailable().
+        // We can improve results if we set AUTO here.
+        if (this.landscape.hasOption('AUTO'))
+          cjt.print.page_orientation = { type: 'AUTO' };
+      } else if (this.landscape.isUserEdited()) {
         cjt.print.page_orientation =
             {type: this.landscape.getValue() ? 'LANDSCAPE' : 'PORTRAIT'};
       }
       if (this.vendorItems.isCapabilityAvailable() &&
           this.vendorItems.isUserEdited()) {
         var items = this.vendorItems.ticketItems;
         cjt.print.vendor_ticket_item = [];
         for (var itemId in items) {
           if (items.hasOwnProperty(itemId)) {
             cjt.print.vendor_ticket_item.push(
@@ skipping 78 matching lines @@
     onDocumentInfoChange_: function() {
       cr.dispatchSimpleEvent(this, PrintTicketStore.EventType.DOCUMENT_CHANGE);
     },
   };
 
   // Export
   return {
     PrintTicketStore: PrintTicketStore
   };
 });