[JonnyShuali]

Returning a WebRTC policy to an earlier/base value could leave an intervening policy active: exact-token deduplication retained the first occurrence. Treat --webrtc-ip-handling-policy as a singleton whose last value wins during both runtime-file merging and launcher merging. Other flag merge behavior is unchanged.

Validation: the new two-stage merge regression failed before the fix and passes for native, suppressed and emulated transitions. The complete server short unit suite passed, excluding Docker e2e tests. No browser-engine binary or image was rebuilt.

Publish this launcher fix in any image approved for explicit WebRTC policy rollout. Verify rollback to a value already present in base flags before approving that image's digest.

---

Note

Low Risk
Scoped change to flag-merge deduplication for one Chromium switch, with unit test coverage; launcher behavior for other flags is unchanged.

Overview
Chromium flag merging now treats --webrtc-ip-handling-policy as a singleton where the last value wins (matching Chromium), instead of keeping the first token during exact-string dedupe. That fixes rollbacks and runtime updates where an older policy could stick when merging base env flags with persisted runtime overlays.

A regression test exercises two-stage merges (MergeFlags then MergeFlagsWithRuntimeTokens) across policy transitions so the final launcher flags always carry a single, latest policy value.

^{Reviewed by Cursor Bugbot for commit 35ced7c. Bugbot is set up for automated code reviews on this repo. Configure here.}

[JonnyShuali]

cursor review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 35ced7c. Configure here.}