Dead Code Cleanup

The first patch removed the dialog. This one caught the references I missed.

Bug 2010586 | D279160 | Reviewers: manuel, tschuster, kpatenio

The Problem

After the old dialog removal landed, there were still references to privacy.sanitize.useOldClearHistoryDialog lurking in the codebase. The backup component and the C++ content security allowlist both had stale entries.

The Fix

Backup component (BackupResource.sys.mjs, FormHistoryBackupResource.sys.mjs, SiteSettingsBackupResource.sys.mjs):

These files had lazy pref getters for both the old and new shutdown prefs, with a conditional branch:

// Before: branched on which dialog was active
if (!lazy.useOldClearHistoryDialog) {
  if (lazy.isHistoryClearedOnShutdown2) {
    return false;
  }
} else if (lazy.isHistoryClearedOnShutdown) {
  return false;
}

// After: just the v2 pref, no branching
if (lazy.isHistoryClearedOnShutdown) {
  return false;
}

The old pref getters for useOldClearHistoryDialog and the v1 shutdown prefs were removed entirely.

C++ allowlist (nsContentSecurityUtils.cpp):

Removed entries for sanitize.xhtml and clearSiteData.xhtml from the content security allowlist. These files no longer exist, so they don’t need to be whitelisted.

Total: 6 files changed, -74 lines.

What I Learned

1. Follow-up patches are part of the job. Large removals almost always leave stragglers. Filing the follow-up bug immediately after the first patch lands is good practice, because you’ll find the stragglers in the days after landing, not during the initial review.