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

chrome/browser/resources/print_preview/print_preview.js

Index: chrome/browser/resources/print_preview/print_preview.js
diff --git a/chrome/browser/resources/print_preview/print_preview.js b/chrome/browser/resources/print_preview/print_preview.js
index ac3a0ab789135db2746d6fe3b522398b759867d9..cb42a755311b83d260fc310b46780eaed1c9edf8 100644
--- a/chrome/browser/resources/print_preview/print_preview.js
+++ b/chrome/browser/resources/print_preview/print_preview.js
@@ -285,7 +285,10 @@ cr.define('print_preview', function() {
           this.nativeLayer_,
           print_preview.NativeLayer.EventType.PRIVET_PRINT_FAILED,
           this.onPrivetPrintFailed_.bind(this));
-
+      this.tracker.add(
+          this.nativeLayer_,
+          print_preview.NativeLayer.EventType.MANIPULATE_SETTINGS_FOR_TEST,
+          this.onManipulateSettingsForTest_.bind(this));
 
       this.tracker.add(
           $('system-dialog-link'),
@@ -691,6 +694,7 @@ cr.define('print_preview', function() {
     onPreviewGenerationDone_: function() {
       this.isPreviewGenerationInProgress_ = false;
       this.printHeader_.isPrintButtonEnabled = true;
+      this.nativeLayer_.previewReadyForTest();
       this.printIfReady_();
     },
 
@@ -890,6 +894,71 @@ cr.define('print_preview', function() {
     },
 
     /**
+     * Called when the print preview settings need to be changed for testing.
+     * @param {Event} event Event object that contains the option that is to
+     *     be changed and what to set that option.
+     * @private
+     */
+    onManipulateSettingsForTest_: function(event) {
+      if ('selectSaveAsPdfDestination' in event.settings) {
+        var destinations = this.destinationStore_.destinations();
+        var pdfDestination = null;
+        for (var i = 0; i < destinations.length; i++) {
+          if (destinations[i].id ==
+              print_preview.Destination.GooglePromotedId.SAVE_AS_PDF) {
+            pdfDestination = destinations[i];
+            break;
+          }
+        }
+
+        if (pdfDestination)
+          this.destinationStore_.selectDestination(pdfDestination);
+        else
+          this.nativeLayer_.previewFailedForTest();
+      } else if ('layoutSettings' in event.settings) {
+        var element = document.querySelector(
+            event.settings.layoutSettings.portrait ?
+                '.layout-settings-portrait-radio' :
+                '.layout-settings-landscape-radio');
+        if (element.clicked)
+          this.nativeLayer_.previewReadyForTest();
+        else
+          element.click();
+      } else if ('pageRange' in event.settings) {
+        var textbox = document.querySelector('.page-settings-custom-input');
+        if (textbox.value == event.settings.pageRange) {
+          this.nativeLayer_.previewReadyForTest();
+        } else {
+          textbox.value = event.settings.pageRange;
+          document.querySelector('.page-settings-custom-radio').click();
+        }
+      } else if ('headersAndFooters' in event.settings) {
+        var checkbox = document.querySelector('.header-footer-checkbox');
+        if (event.settings.headersAndFooters == checkbox.checked)
+          this.nativeLayer_.previewReadyForTest();
+        else
+          checkbox.click();
+      } else if ('backgroundColorsAndImages' in event.settings) {
+        var checkbox = document.querySelector('.css-background-checkbox');
+        if (event.settings.backgroundColorsAndImages == checkbox.checked)
+          this.nativeLayer_.previewReadyForTest();
+        else
+          checkbox.click();
+      } else if ('margins' in event.settings) {
+        var combobox = document.querySelector('.margin-settings-select');
+        if (event.settings.margins == combobox.selectedIndex) {
+          this.nativeLayer_.previewReadyForTest();
+        } else if (event.settings.margins >= 0 &&
+                   event.settings.margins < combobox.length) {
+          combobox.selectedIndex = event.settings.margins;
+          this.marginSettings_.onSelectChange_();
+        } else {
+          this.nativeLayer_.previewFailedForTest();
+        }
+      }
+    },
+
+    /**
      * Called when the open-cloud-print-dialog link is clicked. Opens the Google
      * Cloud Print web dialog.
      * @private