Desktop PWAs: AppListTestBase cleanup

DesktopPWAsWithoutExtensions has shipped and
AppList tests are no longer parameterized, so
branching on kDesktopPWAsWithoutExtensions
is no longer required.

Bug: 1065748
Change-Id: I5ffc8cefc65e7526fd25c486967e08798481c263
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2462890
Commit-Queue: Nancy Wang <nancylingwang@chromium.org>
Auto-Submit: Eric Willigers <ericwilligers@chromium.org>
Reviewed-by: Nancy Wang <nancylingwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815934}

chrome/browser/ui/app_list/app_list_test_util.cc

@@ -44,8 +44,7 @@ void AppListTestBase::SetUp() {
   InitializeInstalledExtensionService(pref_path, source_install_dir);
   service_->Init();
 
-  if (base::FeatureList::IsEnabled(features::kDesktopPWAsWithoutExtensions))
-    ConfigureWebAppProvider();
+  ConfigureWebAppProvider();
 
   // Let any async services complete their set-up.
   base::RunLoop().RunUntilIdle();