Issue 6786 - Switch Safari 12+ users to content blocking API

options.js

Index: options.js
diff --git a/options.js b/options.js
index f1a3c1d817061ba58b3fd78ce6c65f10c1e280e2..c384316732cc72ce5b766f23c3383fa4e7fc4bcb 100644
--- a/options.js
+++ b/options.js
@@ -17,6 +17,9 @@
 
 "use strict";
 
+var applicatonVersion = navigator.userAgent.match(/Version\/([\d.]+)/)[1];
+var majorApplicationVersion = parseInt(applicatonVersion.split(".")[0], 10);
+
 /**
  * Creates a wrapping function used to conveniently send a type of message.
  *
@@ -158,11 +161,14 @@ function loadOptions()
     // running Safari and both the legacy and content blocking APIs are
     // available.
     document.getElementById("safariContentBlockerContainer").hidden = !(
-      features.safariContentBlocker &&
-      typeof safari != "undefined" &&
-      "canLoad" in safari.self.tab &&
-      "onbeforeload" in Element.prototype
+      majorApplicationVersion >= 12 || (
+        features.safariContentBlocker &&
+        typeof safari != "undefined" &&
+        "canLoad" in safari.self.tab &&
+        "onbeforeload" in Element.prototype
+      )
     );
+    document.getElementById("safariContentBlocker").disabled = majorApplicationVersion >= 12;
   });
   getPref("notifications_showui", function(notifications_showui)
   {