feat: enable BrowserOS onboarding

[Nikhil (shadowfax92)]

Summary

• remove the BrowserOS product exclusion from the existing onboarding eligibility check
• preserve regular-profile, initial-profile, off-the-record, and completion restrictions
• refresh the canonical Chromium patch without changing onboarding UI resources or startup plumbing

Design

The existing ProfilePicker launch and onboarding bridge are already product-neutral. This change only allows BrowserOS builds through ShouldShow(); the patch remains owned by the existing onboarding-import feature.

Test plan

• sfmux pool build -- autoninja -C out/Default_browseros_arm64 chrome
• extraction verifier: 1/1 byte-match and 1/1 apply-check

[Nikhil (shadowfax92)]

Greptile (@greptileai) review

[Nikhil (shadowfax92)]

Claude (@claude) review

[claude]

Claude finished Nikhil (@shadowfax92)'s task in 1m 48s —— View job

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Code Review

• Gather context (PR diff, call sites, related patch files)
• Review the patch logic
• Post findings

Summary: This is a small, well-scoped patch that removes the IsBrowserOSProduct() early-return from browseros::onboarding::ShouldShow(), while keeping the regular-profile / initial-profile / off-the-record / already-completed guards intact.

Analysis of the change

Looking at the call site in chrome/browser/ui/startup/startup_browser_creator.cc (StartupBrowserCreator::LaunchBrowser):

if (browseros::IsBrowserOSProduct()) {
  browseros::onboarding::NeutralizeUpstreamFirstRun();
}

if (!command_line.HasSwitch(switches::kNoFirstRun) &&
    browseros::onboarding::ShouldShow(profile)) {
  ...
  ProfilePicker::Show(ProfilePicker::Params::ForFirstRun(...));
  return;
}

Before this patch, ShouldShow() unconditionally returned false whenever IsBrowserOSProduct() was true — meaning the BrowserOS onboarding UI could never actually show on BrowserOS builds, which looks like a self-defeating leftover guard (probably from when the feature was still being staged behind a flag). Removing it is consistent with the call site, which already handles IsBrowserOSProduct()-specific behavior separately (NeutralizeUpstreamFirstRun()), and lets ShouldShow() focus purely on profile-eligibility.

Observations (non-blocking):

1. No behavior change for non-BrowserOS Chromium builds — the other guards (IsRegularProfile(), IsOffTheRecord(), initial-profile check, kOnboardingCompleted) are untouched, so this is a targeted, low-risk change.
2. Patch file format — since this file is itself a generated Chromium patch (diff-of-a-diff), the usual concerns (line-count header @@ -0,0 +1,N @@ and blob index hash staying consistent with the body) apply. Worth double-checking the extraction verifier output mentioned in the test plan (1/1 byte-match, 1/1 apply-check) was run against the latest patch bundle, since patch files are easy to get out of sync by hand.
3. Header comment (browseros_onboarding_prefs.h) already just says "Returns whether onboarding should interrupt startup for profile" — generic enough that no doc update was needed here, good.
4. No test coverage changes — reasonable given this is a Chromium-side C++ patch rather than TS/JS code with a local test harness for this repo.

Overall this looks correct and matches its stated intent — removing an accidental self-exclusion so BrowserOS onboarding actually surfaces on BrowserOS builds, without touching the rest of the eligibility logic or startup plumbing.

[greptile-apps]

Greptile Summary

This PR enables the existing onboarding flow for BrowserOS by removing the product-specific exclusion from ShouldShow(), while retaining profile eligibility and completion checks.

• Removes the IsBrowserOSProduct() early return and now-unused product header.
• Preserves regular-profile, initial-profile, off-the-record, and completed-onboarding restrictions.
• Refreshes the stored Chromium patch representing the onboarding preference implementation.

Confidence Score: 5/5

The PR appears safe to merge because the newly enabled path uses the existing product-neutral onboarding flow and preserves all other eligibility restrictions.

The changed guard removal aligns with the shared onboarding controller, WebUI registration, first-run integration, and universally registered completion preference, with no supported blocking or non-blocking defect remaining.

Important Files Changed

Filename	Overview
packages/browseros/chromium_patches/chrome/browser/browseros/onboarding/browseros_onboarding_prefs.cc	Removes the BrowserOS product exclusion from the stored Chromium onboarding eligibility implementation; no actionable regression was identified.

_{Reviews (1): Last reviewed commit: "feat(patches): enable BrowserOS onboardi..." | Re-trigger Greptile}