fixup! Bug 26345: Hide tracking protection UI

Bug 42679: Re-hide the tracking protections UI.

We hide the toolbar button with CSS.

We hide the preferences using data-hidden-from-search.

browser/components/preferences/privacy.inc.xhtml

@@ -15,7 +15,7 @@
 </hbox>
 
 <!-- Tracking / Content Blocking -->
-<groupbox id="trackingGroup" data-category="panePrivacy" hidden="true" aria-describedby="contentBlockingDescription" class="highlighting-group">
+<groupbox id="trackingGroup" data-category="panePrivacy" data-hidden-from-search="true" hidden="true" aria-describedby="contentBlockingDescription" class="highlighting-group">
   <label id="contentBlockingHeader"><html:h2 data-l10n-id="content-blocking-enhanced-tracking-protection"/></label>
   <vbox data-subcategory="trackingprotection">
     <hbox align="start">

browser/themes/shared/identity-block/identity-block.css

@@ -230,6 +230,9 @@
 /* TRACKING PROTECTION ICON */
 
 #tracking-protection-icon-container {
+  /* Always hide the tracking toolbar button in Base Browser.
+   * tor-browser#26345. */
+  display: none !important;
   padding-inline: var(--urlbar-icon-padding);
   border-radius: var(--urlbar-icon-border-radius);
   /* This is needed in order to position the blue dot indicator. */