[webui][ntp] Enable doodles on themed and dark mode NTPs

Fixed: 688960
Change-Id: I71631b7a6fa0ccda9596eae0517b349ef8fe9675
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2262058Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: Tibor Goldschwendt <tiborg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#782045}

chrome/browser/search/ntp_features.cc

@@ -66,7 +66,7 @@ const base::Feature kWebUIRealbox{"WebUIRealbox",
 
 // If enabled, the Doodle will be shown on themed and dark mode NTPs.
 const base::Feature kWebUIThemeModeDoodles{"WebUIThemeModeDoodles",
-                                           base::FEATURE_DISABLED_BY_DEFAULT};
+                                           base::FEATURE_ENABLED_BY_DEFAULT};
 
 bool IsRealboxEnabled() {
   if (!base::FeatureList::IsEnabled(omnibox::kNewSearchFeatures))