Refactor do not track code.

lib/web.js

@@ -48,26 +48,17 @@ export const hook = (_this, method, callback) => {
 };
 
 export const doNotTrack = () => {
-  if (
-    window.doNotTrack ||
-    navigator.doNotTrack ||
-    navigator.msDoNotTrack ||
-    (window.external && 'msTrackingProtectionEnabled' in window.external)
-  ) {
-    if (
-      window.doNotTrack == '1' ||
-      navigator.doNotTrack == 'yes' ||
-      navigator.doNotTrack == '1' ||
-      navigator.msDoNotTrack == '1' ||
-      (window.external &&
-        window.external.msTrackingProtectionEnabled &&
-        window.external.msTrackingProtectionEnabled())
-    ) {
-      return true;
-    } else {
-      return false;
-    }
-  } else {
-    return false;
-  }
+  const { doNotTrack, navigator, external } = window;
+
+  const msTracking = () => {
+    return (
+      external &&
+      typeof external.msTrackingProtectionEnabled === 'function' &&
+      external.msTrackingProtectionEnabled()
+    );
+  };
+
+  const dnt = doNotTrack || navigator.doNotTrack || navigator.msDoNotTrack || msTracking();
+
+  return dnt === true || dnt === 1 || dnt === 'yes' || dnt === '1';
 };