Add base.js to app remoting feedback dialog.

BUG=b/19550404

Review URL: https://codereview.chromium.org/968263003

Cr-Commit-Position: refs/heads/master@{#318744}

remoting/webapp/app_remoting/html/feedback_consent.html

@@ -13,6 +13,7 @@ found in the LICENSE file.
     <link rel="stylesheet" href="feedback_consent.css">
     <link rel="stylesheet" href="main.css">
     <link rel="stylesheet" href="message_window.css">
+    <script src="base.js"></script>
     <script src="error.js"></script>
     <script src="feedback_consent.js"></script>
     <script src="oauth2_api_impl.js"></script>