Some Linux clients encrypted OSCrypt data with a key derived from an empty
passphrase (crbug.com/1195256). Chromium retries every failed v10/v11 record
with that key, so records it can still read were being skipped here. The key
material now carries the empty-passphrase key on Linux and the decryptor
retries with it when a record's own key fails — and only then, matching
Chromium: a record whose own key is missing entirely stays skipped.

Also drops an unexplained diagnostics suppression from ChromiumKeys.test.ts
that had nothing to suppress.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>