Add new feature flag for the Unified Review Banner

Review Request #10187 — Created Sept. 27, 2018 and submitted — Latest diff uploaded


Review Board


This is the first step of the larger project of creating the Unified
Review Banner Base Shell. Adding this feature flag will allow us to
toggle between the current banner experience and the new Unified Review
Banner experience to allow development on the Unified Banner to continue
without breaking the current experience.

Out of scope for this patch: using the feature flag to toggle between
the two experiences (will come in the next patch).

  • Ran all JS Unit tests (all pass)
  • Set the value in as
    'reviews.unified_banner': True/False

and tested output of RB.EnabledFeatures.unifiedBanner in
ReviewablePage.es6.js file (where the Unified Banner will be