doc: Remove 'dnt_helper.js'

This file is totally useless, because it's an inner-used helper that is
for publishment of doc files.

PR-URL: https://github.com/nodejs/node/pull/22595
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/api_assets/dnt_helper.js

@@ -1,49 +0,0 @@
-/**
- * http://schalkneethling.github.io/blog/2015/11/06/respect-user-choice-do-not-track/
- * https://github.com/schalkneethling/dnt-helper/blob/master/js/dnt-helper.js
- *
- * Returns true or false based on whether doNotTack is enabled. It also takes into account the
- * anomalies, such as !bugzilla 887703, which effect versions of Fx 31 and lower. It also handles
- * IE versions on Windows 7, 8 and 8.1, where the DNT implementation does not honor the spec.
- * @see https://bugzilla.mozilla.org/show_bug.cgi?id=1217896 for more details
- * @params {string} [dnt] - An optional mock doNotTrack string to ease unit testing.
- * @params {string} [userAgent] - An optional mock userAgent string to ease unit testing.
- * @returns {boolean} true if enabled else false
- */
-function _dntEnabled(dnt, userAgent) {
-
-    'use strict';
-
-    // for old version of IE we need to use the msDoNotTrack property of navigator
-    // on newer versions, and newer platforms, this is doNotTrack but, on the window object
-    // Safari also exposes the property on the window object.
-    var dntStatus = dnt || navigator.doNotTrack || window.doNotTrack || navigator.msDoNotTrack;
-    var ua = userAgent || navigator.userAgent;
-
-    // List of Windows versions known to not implement DNT according to the standard.
-    var anomalousWinVersions = ['Windows NT 6.1', 'Windows NT 6.2', 'Windows NT 6.3'];
-
-    var fxMatch = ua.match(/Firefox\/(\d+)/);
-    var ieRegEx = /MSIE|Trident/i;
-    var isIE = ieRegEx.test(ua);
-    // Matches from Windows up to the first occurrence of ; un-greedily
-    // http://www.regexr.com/3c2el
-    var platform = ua.match(/Windows.+?(?=;)/g);
-
-    // With old versions of IE, DNT did not exist so we simply return false;
-    if (isIE && typeof Array.prototype.indexOf !== 'function') {
-        return false;
-    } else if (fxMatch && parseInt(fxMatch[1], 10) < 32) {
-        // Can't say for sure if it is 1 or 0, due to Fx bug 887703
-        dntStatus = 'Unspecified';
-    } else if (isIE && platform && anomalousWinVersions.indexOf(platform.toString()) !== -1) {
-        // default is on, which does not honor the specification
-        dntStatus = 'Unspecified';
-    } else {
-        // sets dntStatus to Disabled or Enabled based on the value returned by the browser.
-        // If dntStatus is undefined, it will be set to Unspecified
-        dntStatus = { '0': 'Disabled', '1': 'Enabled' }[dntStatus] || 'Unspecified';
-    }
-
-    return dntStatus === 'Enabled' ? true : false;
-}

tools/doc/html.js

@@ -79,9 +79,17 @@ function toHTML({ input, content, filename, nodeVersion, analytics }, cb) {
 
   if (analytics) {
     HTML = HTML.replace('<!-- __TRACKING__ -->', `
-    <script src="assets/dnt_helper.js"></script>
+    <script type="text/javascript">
-    <script>
+      // In all the browsers we'll get '1' or 'yes' (FF 32 or above) as a string
-      if (!_dntEnabled()) {
+      // value when enabling 'DO NOT TRACK'.
+      // For more:
+      // https://developer.mozilla.org/en-US/docs/Web/API/navigator/doNotTrack
+      function isDoNotTrack() {
+        var isDoNotTrackEnabled = navigator.doNotTrack || window.doNotTrack ||
+               navigator.msDoNotTrack;
+        return isDoNotTrackEnabled === '1' || isDoNotTrackEnabled === 'yes';
+      }
+      if (!isDoNotTrack()) {
         (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;
         i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},
         i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];