Bug 1484832 - Update DNT section for Content Blocking. r=Gijs,flod

Differential Revision: https://phabricator.services.mozilla.com/D4517

--HG--
extra : moz-landing-system : lando

browser/components/preferences/in-content/privacy.js

@@ -578,6 +578,14 @@ var gPrivacyPane = {
       document.getElementById(id).hidden = contentBlockingUiEnabled != visibleState[id];
     }
 
+    // Update the Do Not Track section to not mention "Tracking Protection".
+    if (contentBlockingUiEnabled) {
+      let dntDefaultRadioItem =
+        document.querySelector("#doNotTrackRadioGroup > radio[value=false]");
+      document.l10n.setAttributes(
+        dntDefaultRadioItem, "do-not-track-option-default-content-blocking");
+    }
+
     // Allow turning off the "(recommended)" label using a pref
     let blockCookiesFromTrackers = document.getElementById("blockCookiesFromTrackers");
     if (contentBlockingCookiesAndSiteDataRejectTrackersRecommended) {

browser/locales/en-US/browser/preferences/preferences.ftl

@@ -6,6 +6,8 @@ do-not-track-description = Send websites a “Do Not Track” signal that you do
 do-not-track-learn-more = Learn more
 do-not-track-option-default =
     .label = Only when using Tracking Protection
+do-not-track-option-default-content-blocking =
+    .label = Only when { -brand-short-name } is set to block Detected Trackers
 do-not-track-option-always =
     .label = Always