Print Preview: Fix top level directory compile errors

chrome/browser/resources/print_preview/previewarea/preview_area.js

Index: chrome/browser/resources/print_preview/previewarea/preview_area.js
diff --git a/chrome/browser/resources/print_preview/previewarea/preview_area.js b/chrome/browser/resources/print_preview/previewarea/preview_area.js
index a8f754eda2cee6253b5abbb649aefcb81725f962..d7f861eef5d1fbee404222be38f9d516a43e0911 100644
--- a/chrome/browser/resources/print_preview/previewarea/preview_area.js
+++ b/chrome/browser/resources/print_preview/previewarea/preview_area.js
@@ -293,8 +293,8 @@ cr.define('print_preview', function() {
     /**
      * Set a callback that gets called when a key event is received that
      * originates in the plugin.
-     * @param {function(Event)} callback The callback to be called with a key
-     *     event.
+     * @param {function(KeyboardEvent)} callback The callback to be called with
+     *     a key event.
      */
     setPluginKeyEventCallback: function(callback) {
       this.keyEventCallback_ = callback;