WebUI NTP: render middle slot promo from structured data

Bug: 1112992
Change-Id: I7f6969c640e71cee455d64373d95f5d14ea48474
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2366090
Commit-Queue: Esmael Elmoslimany <[email protected]>
Reviewed-by: Lei Zhang <[email protected]>
Reviewed-by: Alex Gough <[email protected]>
Reviewed-by: Nicolas Ouellet-Payeur <[email protected]>
Reviewed-by: Moe Ahmadi <[email protected]>
Reviewed-by: Tibor Goldschwendt <[email protected]>
Auto-Submit: Esmael Elmoslimany <[email protected]>
Cr-Commit-Position: refs/heads/master@{#802453}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index a40dc590..c5abdc1 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1430,11 +1430,9 @@
         {features::kPromoBrowserCommandIdParam, "1"}};
 const FeatureEntry::FeatureVariation kPromoBrowserCommandsVariations[] = {
     {"- Unknown Command", kPromoBrowserCommandUnknownCommandParam,
-     base::size(kPromoBrowserCommandUnknownCommandParam),
-     "t4237555" /* variation_id */},
+     base::size(kPromoBrowserCommandUnknownCommandParam), nullptr},
     {"- Open Safety Check", kPromoBrowserCommandOpenSafetyCheckCommandParam,
-     base::size(kPromoBrowserCommandOpenSafetyCheckCommandParam),
-     "t4237555" /* variation_id */}};
+     base::size(kPromoBrowserCommandOpenSafetyCheckCommandParam), nullptr}};
 
 #if defined(OS_ANDROID)
 const FeatureEntry::FeatureParam kTranslateForceTriggerOnEnglishHeuristic[] = {