Do not check isOobeUi() when demo mode accelerator is triggered.

Showing demo mode setup UI is already guarded by the appropriate
screen group check. This check is sufficient.

Change-Id: I61478bb0e0a4933a2f6869781b7a9b115d926f08
Reviewed-on: https://chromium-review.googlesource.com/1104974Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Commit-Queue: Aga Wronska <agawronska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568125}

ui/login/display_manager.js

@@ -474,7 +474,7 @@ cr.define('cr.ui.login', function() {
         chrome.send('setOobeBootstrappingSlave');
       } else if (name == ACCELERATOR_DEMO_MODE) {
         if (DEMO_MODE_SETUP_AVAILABLE_SCREEN_GROUP.indexOf(currentStepId) !=
-          -1 && this.isOobeUI()) {
+            -1) {
           this.showEnableDemoModeDialog_();
         }
       } else if (name == ACCELERATOR_SEND_FEEDBACK) {