Add support for starting an extension print job to print preview

chrome/browser/resources/print_preview/native_layer.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.exportPath('print_preview');
 
 /**
  * @typedef {{selectSaveAsPdfDestination: boolean,
  *            layoutSettings.portrait: boolean,
  *            pageRange: string,
@@ skipping 309 matching lines @@
      */
     startPrint: function(destination, printTicketStore, cloudPrintInterface,
                          documentInfo, opt_isOpenPdfInPreview,
                          opt_showSystemDialog) {
       assert(printTicketStore.isTicketValid(),
              'Trying to print when ticket is not valid');
 
       assert(!opt_showSystemDialog || (cr.isWindows && destination.isLocal),
              'Implemented for Windows only');
 
-      // TODO(tbarzic): Implement this.
-      assert(!destination.isExtension,
-             'Printing to extension printers not yet implemented.');
-
       var ticket = {
         'pageRange': printTicketStore.pageRange.getDocumentPageRanges(),
         'mediaSize': printTicketStore.mediaSize.getValue(),
         'pageCount': printTicketStore.pageRange.getPageNumberSet().size,
         'landscape': printTicketStore.landscape.getValue(),
         'color': this.getNativeColorModel_(destination, printTicketStore.color),
         'headerFooterEnabled': printTicketStore.headerFooter.getValue(),
         'marginsType': printTicketStore.marginsType.getValue(),
         'generateDraftData': true, // TODO(rltoscano): What should this be?
         'duplex': printTicketStore.duplex.getValue() ?
             NativeLayer.DuplexMode.LONG_EDGE : NativeLayer.DuplexMode.SIMPLEX,
         'copies': printTicketStore.copies.getValueAsNumber(),
         'collate': printTicketStore.collate.getValue(),
         'shouldPrintBackgrounds': printTicketStore.cssBackground.getValue(),
         'shouldPrintSelectionOnly': printTicketStore.selectionOnly.getValue(),
         'previewModifiable': documentInfo.isModifiable,
         'printToPDF': destination.id ==
             print_preview.Destination.GooglePromotedId.SAVE_AS_PDF,
         'printWithCloudPrint': !destination.isLocal,
         'printWithPrivet': destination.isPrivet,
+        'printWithExtension': destination.isExtension,
         'deviceName': destination.id,
         'isFirstRequest': false,
         'requestID': -1,
         'fitToPageEnabled': printTicketStore.fitToPage.getValue(),
         'pageWidth': documentInfo.pageSize.width,
         'pageHeight': documentInfo.pageSize.height,
         'showSystemDialog': opt_showSystemDialog
       };
 
       if (!destination.isLocal) {
@@ skipping 10 matching lines @@
         var orientationEnum =
             print_preview.ticket_items.CustomMargins.Orientation;
         ticket['marginsCustom'] = {
           'marginTop': customMargins.get(orientationEnum.TOP),
           'marginRight': customMargins.get(orientationEnum.RIGHT),
           'marginBottom': customMargins.get(orientationEnum.BOTTOM),
           'marginLeft': customMargins.get(orientationEnum.LEFT)
         };
       }
 
       if (destination.isPrivet) {

[Vitaly Buka (NO REVIEWS), 2015/02/11 22:39:26]

destination.isPrivet || destination.isExtension

[tbarzic, 2015/02/11 22:48:18]

Done.

         ticket['ticket'] = printTicketStore.createPrintTicket(destination);
         ticket['capabilities'] = JSON.stringify(destination.capabilities);
       }
 
+      if (destination.isExtension) {
+        ticket['ticket'] = printTicketStore.createPrintTicket(destination);
+        ticket['capabilities'] = JSON.stringify(destination.capabilities);
+      }
+
       if (opt_isOpenPdfInPreview) {
         ticket['OpenPDFInPreview'] = true;
       }
 
       chrome.send('print', [JSON.stringify(ticket)]);
     },
 
     /** Requests that the current pending print request be cancelled. */
     startCancelPendingPrint: function() {
       chrome.send('cancelPendingPrintRequest');
@@ skipping 634 matching lines @@
       return this.serializedAppStateStr_;
     }
   };
 
   // Export
   return {
     NativeInitialSettings: NativeInitialSettings,
     NativeLayer: NativeLayer
   };
 });