Bug 1737198 - Part 3: Remove TRR blocklist cleanup code. r=valentin,necko-reviewers

Reverts bug 1651672 / rev D86520. It's been a few releases,
we can remove this cleanup code.

Differential Revision: https://phabricator.services.mozilla.com/D132107

modules/libpref/init/StaticPrefList.yaml

@@ -9922,14 +9922,6 @@
   value: true
   mirror: always
 
-# If this pref is false, a task will be dispatched to remove the file from the
-# disk and the pref will be set to true.
-# It can probably be removed after a few releases.
-- name: network.trr.blocklist_cleanup_done
-  type: RelaxedAtomicBool
-  value: false
-  mirror: always
-
 # If we should wait for captive portal confirmation before enabling TRR
 - name: network.trr.wait-for-portal
   type: RelaxedAtomicBool

netwerk/dns/TRRService.cpp

@@ -3,7 +3,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "nsAppDirectoryServiceDefs.h"
 #include "nsCharSeparatedTokenizer.h"
 #include "nsComponentManagerUtils.h"
 #include "nsDirectoryServiceUtils.h"
@@ -119,32 +118,6 @@ bool TRRService::CheckCaptivePortalIsPassed() {
   return result;
 }
 
-static void RemoveTRRBlocklistFile() {
-  MOZ_ASSERT(NS_IsMainThread(), "Getting the profile dir on the main thread");
-
-  nsCOMPtr<nsIFile> file;
-  nsresult rv =
-      NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(file));
-  if (NS_FAILED(rv)) {
-    return;
-  }
-
-  rv = file->AppendNative("TRRBlacklist.txt"_ns);
-  if (NS_FAILED(rv)) {
-    return;
-  }
-
-  // Dispatch an async task that removes the blocklist file from the profile.
-  rv = NS_DispatchBackgroundTask(
-      NS_NewRunnableFunction("RemoveTRRBlocklistFile::Remove",
-                             [file] { file->Remove(false); }),
-      NS_DISPATCH_EVENT_MAY_BLOCK);
-  if (NS_FAILED(rv)) {
-    return;
-  }
-  Preferences::SetBool("network.trr.blocklist_cleanup_done", true);
-}
-
 static void EventTelemetryPrefChanged(const char* aPref, void* aData) {
   Telemetry::SetEventRecordingEnabled(
       "network.dns"_ns,
@@ -194,15 +167,6 @@ nsresult TRRService::Init() {
     }
 
     sTRRBackgroundThread = thread;
-
-    if (!StaticPrefs::network_trr_blocklist_cleanup_done()) {
-      // Dispatch an idle task to the main thread that gets the profile dir
-      // then attempts to delete the blocklist file on a background thread.
-      Unused << NS_DispatchToMainThreadQueue(
-          NS_NewCancelableRunnableFunction("RemoveTRRBlocklistFile::GetDir",
-                                           [] { RemoveTRRBlocklistFile(); }),
-          EventQueuePriority::Idle);
-    }
   }
 
   mODoHService = new ODoHService();