GitLab

This reverts commit 4ad50af3.

Reason for revert: Breaks is_chrome_branded builds -- startup_tab_provider_unittest.cc is still referencing members of StandardOnboardingTabsParams that were removed.

Original change's description:
> NUX Onboarding: clean up build process.
> 
> This CL cleans up the remnants of the NUX Experiments bulid configs. Including:
> - removing os_win and google_chrome_branded build flag.
> - removing prefs that tracks if the one-off NUX experiments were seen.
> - fixing closure compile errors now that it needs to build on non-official bots.
> 
> Bug: 874153
> Change-Id: I03c1ed09c54f5ba91944bcb31837e80a0ee1fc74
> Reviewed-on: https://chromium-review.googlesource.com/c/1252906
> Commit-Queue: Scott Chen <scottchen@chromium.org>
> Reviewed-by: Scott Violet <sky@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#596432}

TBR=sky@chromium.org,scottchen@chromium.org

Change-Id: I643cfa84bb9da07b4e1ebf8a9481d0ac32aeea90
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 874153
Reviewed-on: https://chromium-review.googlesource.com/c/1260128Reviewed-by: Greg Thompson <grt@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596535}