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

chrome/browser/resources/print_preview/print_preview.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.
 
 // TODO(rltoscano): Move data/* into print_preview.data namespace
 
 var localStrings = new LocalStrings(templateData);
 
 <include src="component.js"/>
 
@@ skipping 267 matching lines @@
           print_preview.NativeLayer.EventType.SETTINGS_INVALID,
           this.onSettingsInvalid_.bind(this));
       this.tracker.add(
           this.nativeLayer_,
           print_preview.NativeLayer.EventType.DISABLE_SCALING,
           this.onDisableScaling_.bind(this));
       this.tracker.add(
           this.nativeLayer_,
           print_preview.NativeLayer.EventType.PRIVET_PRINT_FAILED,
           this.onPrivetPrintFailed_.bind(this));
-
+      this.tracker.add(
+          this.nativeLayer_,
+          print_preview.NativeLayer.EventType.CLICK_STUFF,
+          this.onClickStuff_.bind(this));
 
       this.tracker.add(
           $('system-dialog-link'),
           'click',
           this.openSystemPrintDialog_.bind(this));
       this.tracker.add(
           $('cloud-print-dialog-link'),
           'click',
           this.onCloudPrintDialogLinkClick_.bind(this));
       this.tracker.add(
@@ skipping 385 matching lines @@
       this.isPreviewGenerationInProgress_ = true;
     },
 
     /**
      * Called when the preview area's preview generation is complete.
      * @private
      */
     onPreviewGenerationDone_: function() {
       this.isPreviewGenerationInProgress_ = false;
       this.printHeader_.isPrintButtonEnabled = true;
+      chrome.send('UILoaded');
       this.printIfReady_();
     },
 
     /**
      * Called when the preview area's preview failed to load.
      * @private
      */
     onPreviewGenerationFail_: function() {
       this.isPreviewGenerationInProgress_ = false;
       this.printHeader_.isPrintButtonEnabled = false;
@@ skipping 178 matching lines @@
      * @param {Event} event Event object representing the failure.
      * @private
      */
     onPrivetPrintFailed_: function(event) {
       console.error('Privet printing failed with error code ' +
                     event.httpError);
       this.printHeader_.setErrorMessage(
         localStrings.getString('couldNotPrint'));
     },
 
+    onClickStuff_: function() {

[Lei Zhang, 2014/06/16 23:12:40]

Are you going to expand this function to have parameters, so its action is not
hard coded to do just one thing, or are you going to have multiple functions to
take different actions?

[ivandavid, 2014/06/17 00:38:56]

I am going to expand this function to take arguments.

[Lei Zhang, 2014/06/17 00:53:26]

If you can continue working on this CL and do this, that would be great.

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

Done.

+      var settings = $('layout-settings');
+      this.destinationStore_.selectDefaultDestination_();
+      var portrait = document.getElementsByClassName(
+          'layout-settings-landscape-radio')[0];
+      if (portrait) {
+        portrait.click();
+      }
+    },
+
     /**
      * Called when the open-cloud-print-dialog link is clicked. Opens the Google
      * Cloud Print web dialog.
      * @private
      */
     onCloudPrintDialogLinkClick_: function() {
       assert(this.uiState_ == PrintPreview.UiState_.READY,
              'Opening Google Cloud Print dialog when not in ready state: ' +
                  this.uiState_);
       setIsVisible($('cloud-print-dialog-throbber'), true);
@@ skipping 132 matching lines @@
 <include src="search/recent_destination_list.js"/>
 <include src="search/destination_list_item.js"/>
 <include src="search/destination_search.js"/>
 <include src="search/search_box.js"/>
 <include src="search/fedex_tos.js"/>
 
 window.addEventListener('DOMContentLoaded', function() {
   printPreview = new print_preview.PrintPreview();
   printPreview.initialize();
 });