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

chrome/browser/resources/print_preview/native_layer.js

Index: chrome/browser/resources/print_preview/native_layer.js
diff --git a/chrome/browser/resources/print_preview/native_layer.js b/chrome/browser/resources/print_preview/native_layer.js
index efdd55b36073695ca5a34c475a299e408e7ea0a9..d69ec668b0b9cddb3b3a0dd2142cf5b1a8b352c8 100644
--- a/chrome/browser/resources/print_preview/native_layer.js
+++ b/chrome/browser/resources/print_preview/native_layer.js
@@ -46,6 +46,8 @@ cr.define('print_preview', function() {
     global['onPrivetCapabilitiesSet'] =
         this.onPrivetCapabilitiesSet_.bind(this);
     global['onPrivetPrintFailed'] = this.onPrivetPrintFailed_.bind(this);
+    global['onEnableManipulateSettingsForTest'] =
+        this.onEnableManipulateSettingsForTest_.bind(this);
   };
 
   /**
@@ -77,7 +79,9 @@ cr.define('print_preview', function() {
     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_FOR_TEST:
+        'print_preview.NativeLayer.MANIPULATE_SETTINGS_FOR_TEST'
   };
 
   /**
@@ -373,6 +377,10 @@ cr.define('print_preview', function() {
       chrome.send('forceOpenNewTab', [url]);
     },
 
+    doneManipulatingSettings: function() {
+      chrome.send('UILoadedForTest');
+    },
+
     /**
      * @param {!Object} initialSettings Object containing all initial settings.
      */
@@ -672,6 +680,49 @@ cr.define('print_preview', function() {
             new Event(NativeLayer.EventType.PRIVET_PRINT_FAILED);
       privetPrintFailedEvent.httpError = http_error;
       this.dispatchEvent(privetPrintFailedEvent);
+    },
+
+    /**
+     * Function that allows for onManipulateSettings to be called
+     * from the native layer, specifically during testing.
+     */
+    onEnableManipulateSettingsForTest_: function() {
+      global['onManipulateSettingsForTest'] =
+          this.onManipulateSettingsForTest_.bind(this);
+    },
+
+    /**
+     * Function call from browsertest to start clicking certain buttons.
+     * @param {string} messageName The setting that is to be manipulated,
+     *    such as the layout settings, or page numbers
+     * @param {string, boolean, undefined} Is the value that we want to
+     *    set the particular setting to. For layout settings, page numbers,
+     *    and margins, its a string. For 'headers and footers' and
+     *    'background colors and images,' its a boolean. For Save as PDF,
+     *    its undefined as it isn't needed.
+     */
+    onManipulateSettingsForTest_: function(messageName, parameter) {
+      var manipulateSettingsEvent =
+          new Event(NativeLayer.EventType.MANIPULATE_SETTINGS_FOR_TEST);
+      manipulateSettingsEvent.messageName = messageName;
+      if (messageName == 'SAVE_AS_PDF') {
+      }
+      else if (messageName == 'LAYOUT_SETTINGS') {
+        manipulateSettingsEvent.isPortrait = 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') {

[Aleksey Shlyapnikov, 2014/06/18 21:57:35]

Move all elses on the same line with }

[ivandavid, 2014/06/20 01:00:25]

Done.

+        manipulateSettingsEvent.margins = parameter;
+      }

[Aleksey Shlyapnikov, 2014/06/18 21:57:35]

Why not pass a dictionary here (for example, similar to
onUpdateWithPrinterCapabilities_) and relieve native_layer of this knowledge?

[ivandavid, 2014/06/20 01:00:25]

Done.

+      this.dispatchEvent(manipulateSettingsEvent);
     }
   };