WebUI NTP: add IframeOneGoogleBar to fieldtrial_testing_config.json

cl/333509607

Bug: 1076506
Change-Id: I265b7655678d0af4b46a72ed715152e531d11b06
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2433998
Commit-Queue: Esmael Elmoslimany <aee@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811637}

chrome/browser/resources/new_tab_page/app.js

@@ -323,7 +323,9 @@ class AppElement extends PolymerElement {
   async loadOneGoogleBar_() {
     if (this.iframeOneGoogleBarEnabled_) {
       const oneGoogleBar = document.querySelector('#oneGoogleBar');
-      oneGoogleBar.remove();
+      if (oneGoogleBar) {
+        oneGoogleBar.remove();
+      }
       return;
     }
 

testing/variations/fieldtrial_testing_config.json

@@ -4563,6 +4563,7 @@
                     "name": "Enabled",
                     "enable_features": [
                         "DisableSearchSuggestChips",
+                        "IframeOneGoogleBar",
                         "NtpWebUI"
                     ]
                 }