dpwa: Remove scoped feature list from SystemWebAppManagerTest

Remove scoped feature list from SystemWebAppManagerTest in
system_web_app_manager_unittest.cc, now that
kDesktopPWAsWithoutExtensions is always true.

Bug: 1065748
Change-Id: Ibf6dc5e53a5ea1a6c37d479a2f17d5efafc8fd22
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2459687Reviewed-by: Alexey Baskakov <loyso@chromium.org>
Commit-Queue: Fabio Rocha <fabio.rocha@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#815156}

chrome/browser/web_applications/system_web_app_manager_unittest.cc

@@ -168,10 +168,7 @@ class SystemWebAppWaiter {
 
 class SystemWebAppManagerTest : public WebAppTest {
  public:
-  SystemWebAppManagerTest() {
-    scoped_feature_list_.InitWithFeatures(
-        {features::kDesktopPWAsWithoutExtensions}, {});
-  }
+  SystemWebAppManagerTest() = default;
   SystemWebAppManagerTest(const SystemWebAppManagerTest&) = delete;
   SystemWebAppManagerTest& operator=(const SystemWebAppManagerTest&) = delete;
 
@@ -365,7 +362,6 @@ class SystemWebAppManagerTest : public WebAppTest {
   }
 
  private:
-  base::test::ScopedFeatureList scoped_feature_list_;
   std::unique_ptr<TestWebAppRegistryController> test_registry_controller_;
   std::unique_ptr<ExternallyInstalledWebAppPrefs>
       externally_installed_app_prefs_;