Remove all the ephemeral apps code.

chrome/browser/background/background_application_list_model.cc

Index: chrome/browser/background/background_application_list_model.cc
diff --git a/chrome/browser/background/background_application_list_model.cc b/chrome/browser/background/background_application_list_model.cc
index ef4aefa723517465bec2c48819b2a9448e72773f..fd2ef5f3bd052df01aceee74801e8269ea1bc387 100644
--- a/chrome/browser/background/background_application_list_model.cc
+++ b/chrome/browser/background/background_application_list_model.cc
@@ -264,11 +264,6 @@ bool BackgroundApplicationListModel::IsBackgroundApp(
   // 2) It is a hosted app, and has a background contents registered or in the
   //    manifest.
 
-  // Ephemeral apps are denied any background activity after their event page
-  // has been destroyed, thus they cannot be background apps.
-  if (extensions::util::IsEphemeralApp(extension.id(), profile))
-    return false;
-
   // Not a background app if we don't have the background permission.
   if (!extension.permissions_data()->HasAPIPermission(
           APIPermission::kBackground)) {