Added a test that currently is able to print to pdf.

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.define('print_preview', function() {
   'use strict';
 
   /**
    * An interface to the native Chromium printing system layer.
    * @constructor
@@ skipping 28 matching lines @@
     global['onDidPreviewPage'] = this.onDidPreviewPage_.bind(this);
     global['updatePrintPreview'] = this.onUpdatePrintPreview_.bind(this);
     global['printScalingDisabledForSourcePDF'] =
         this.onPrintScalingDisabledForSourcePDF_.bind(this);
     global['onDidGetAccessToken'] = this.onDidGetAccessToken_.bind(this);
     global['autoCancelForTesting'] = this.autoCancelForTesting_.bind(this);
     global['onPrivetPrinterChanged'] = this.onPrivetPrinterChanged_.bind(this);
     global['onPrivetCapabilitiesSet'] =
         this.onPrivetCapabilitiesSet_.bind(this);
     global['onPrivetPrintFailed'] = this.onPrivetPrintFailed_.bind(this);
+    global['onManipulateSettings'] = this.onManipulateSettings_.bind(this);
   };
 
   /**
    * Event types dispatched from the Chromium native layer.
    * @enum {string}
    * @const
    */
   NativeLayer.EventType = {
     ACCESS_TOKEN_READY: 'print_preview.NativeLayer.ACCESS_TOKEN_READY',
     CAPABILITIES_SET: 'print_preview.NativeLayer.CAPABILITIES_SET',
@@ skipping 11 matching lines @@
     PAGE_PREVIEW_READY: 'print_preview.NativeLayer.PAGE_PREVIEW_READY',
     PREVIEW_GENERATION_DONE:
         'print_preview.NativeLayer.PREVIEW_GENERATION_DONE',
     PREVIEW_GENERATION_FAIL:
         'print_preview.NativeLayer.PREVIEW_GENERATION_FAIL',
     PRINT_TO_CLOUD: 'print_preview.NativeLayer.PRINT_TO_CLOUD',
     SETTINGS_INVALID: 'print_preview.NativeLayer.SETTINGS_INVALID',
     PRIVET_PRINTER_CHANGED: 'print_preview.NativeLayer.PRIVET_PRINTER_CHANGED',
     PRIVET_CAPABILITIES_SET:
         'print_preview.NativeLayer.PRIVET_CAPABILITIES_SET',
-    PRIVET_PRINT_FAILED: 'print_preview.NativeLayer.PRIVET_PRINT_FAILED'
+    PRIVET_PRINT_FAILED: 'print_preview.NativeLayer.PRIVET_PRINT_FAILED',
+    MANIPULATE_SETTINGS: 'print_preview.NativeLayer.MANIPULATE_SETTINGS'
   };
 
   /**
    * Constant values matching printing::DuplexMode enum.
    * @enum {number}
    */
   NativeLayer.DuplexMode = {
     SIMPLEX: 0,
     LONG_EDGE: 1,
     UNKNOWN_DUPLEX_MODE: -1
@@ skipping 574 matching lines @@
     /**
      * @param {string} http_error The HTTP response code or -1 if not an HTTP
      *    error.
      * @private
      */
     onPrivetPrintFailed_: function(http_error) {
       var privetPrintFailedEvent =
             new Event(NativeLayer.EventType.PRIVET_PRINT_FAILED);
       privetPrintFailedEvent.httpError = http_error;
       this.dispatchEvent(privetPrintFailedEvent);
+    },
+
+    /**
+     * Function call from browsertest to start clicking certain buttons
+     */
+    onManipulateSettings_: function(messageName, parameter) {

[ivandavid, 2014/06/17 21:38:18]

'messageName' is the property of print preview that I want to change and
parameter is what I actually want to change it to.

[Lei Zhang, 2014/06/17 21:57:33]

You should update the JS doc, rather than mentioning it in a code review
comment.

[ivandavid, 2014/06/17 22:59:16]

Done. I think I correctly followed the @param section, however I am not sure,
since |parameter| can be different types. So I listed all the possible types and
the situations in which |parameter| would be of that type.

+      var manipulateSettingsEvent =
+          new Event(NativeLayer.EventType.MANIPULATE_SETTINGS);
+      manipulateSettingsEvent.messageName = messageName;
+      if (messageName == 'SAVE_AS_PDF') {
+      }
+      else if (messageName == 'LAYOUT_SETTINGS') {
+        manipulateSettingsEvent.layoutSettings = parameter;
+      }
+      else if (messageName == 'PAGE_NUMBERS') {
+        manipulateSettingsEvent.pageNumbers = parameter;
+      }
+      else if (messageName == 'HEADERS_AND_FOOTERS') {
+        manipulateSettingsEvent.headersAndFooters = parameter;
+      }
+      else if (messageName == 'BACKGROUND_COLORS_AND_IMAGES') {
+        manipulateSettingsEvent.backgroundColorsAndImages = parameter;
+      }
+      else if (messageName == 'MARGINS') {
+        manipulateSettingsEvent.margins = parameter;
+      }
+      this.dispatchEvent(manipulateSettingsEvent);
     }
   };
 
   /**
    * Initial settings retrieved from the native layer.
    * @param {boolean} isInKioskAutoPrintMode Whether the print preview should be
    *     in auto-print mode.
    * @param {string} thousandsDelimeter Character delimeter of thousands digits.
    * @param {string} decimalDelimeter Character delimeter of the decimal point.
    * @param {!print_preview.MeasurementSystem.UnitType} unitType Unit type of
@@ skipping 165 matching lines @@
       return this.serializedAppStateStr_;
     }
   };
 
   // Export
   return {
     NativeInitialSettings: NativeInitialSettings,
     NativeLayer: NativeLayer
   };
 });