WebUI NTP: disable OneGoogleBar by default to allow finch to control flag

Bug: 1076506
Change-Id: I167596f3b470adbd015ceb1a72ea25abfe6268e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2542669
Auto-Submit: Esmael Elmoslimany <aee@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829038}

components/search/ntp_features.cc

@@ -23,7 +23,7 @@ const base::Feature kDismissPromos{"DismissNtpPromos",
 
 // If enabled, the OneGooleBar is loaded in an iframe. Otherwise, it is inlined.
 const base::Feature kIframeOneGoogleBar{"IframeOneGoogleBar",
-                                        base::FEATURE_ENABLED_BY_DEFAULT};
+                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
 // If enabled, queries that are frequently repeated by the user (and are
 // expected to be issued again) are shown as most visited tiles.