Bug 1567384 - Set oneOffSearchButtons.textbox to UrlbarInput::inputField since there's no real textbox anymore. r=adw

Differential Revision: https://phabricator.services.mozilla.com/D38677

--HG--
extra : moz-landing-system : lando

browser/components/urlbar/UrlbarView.jsm

@@ -904,7 +904,7 @@ class UrlbarView {
     if (enable && UrlbarPrefs.get("oneOffSearches")) {
       this.oneOffSearchButtons.telemetryOrigin = "urlbar";
       this.oneOffSearchButtons.style.display = "";
-      this.oneOffSearchButtons.textbox = this.input.textbox;
+      this.oneOffSearchButtons.textbox = this.input.inputField;
       this.oneOffSearchButtons.view = this;
     } else {
       this.oneOffSearchButtons.telemetryOrigin = null;