LibWeb: Remove underlying realm from SyntheticRealmSettings

This was removed from the ShadowRealm HTML spec integration PR after my
suggestion as it is not used anywhere, and I don't believe it would ever
need to be used in the future or by other specs.

Libraries/LibWeb/Bindings/MainThreadVM.cpp

@@ -583,29 +583,26 @@ ErrorOr<void> initialize_main_thread_vm(HTML::EventLoop::Type type)
             // 5. Set settings's principal realm to O's associated realm
             .principal_realm = object.shape().realm(),
 
-            // 6. Set settings's underlying realm to realm.
-            .underlying_realm = realm,
-
-            // 7. Set settings's module map to a new module map, initially empty.
+            // 6. Set settings's module map to a new module map, initially empty.
             .module_map = realm.create<HTML::ModuleMap>(),
         };
 
-        // 8. Set realm.[[HostDefined]] to settings.
+        // 7. Set realm.[[HostDefined]] to settings.
         realm.set_host_defined(make<Bindings::SyntheticHostDefined>(move(settings), realm.create<Bindings::Intrinsics>(realm)));
 
-        // 9. Set realm.[[GlobalObject]] to globalObject.
+        // 8. Set realm.[[GlobalObject]] to globalObject.
         realm.set_global_object(global_object);
 
-        // 10. Set realm.[[GlobalEnv]] to NewGlobalEnvironment(globalObject, globalObject).
+        // 9. Set realm.[[GlobalEnv]] to NewGlobalEnvironment(globalObject, globalObject).
         realm.set_global_environment(realm.heap().allocate<JS::GlobalEnvironment>(global_object, global_object));
 
-        // 11. Perform ? SetDefaultGlobalBindings(realm).
+        // 10. Perform ? SetDefaultGlobalBindings(realm).
         set_default_global_bindings(realm);
 
         // NOTE: This needs to be done after initialization so that the realm has an intrinsics in its [[HostDefined]]
         global_object->initialize_web_interfaces();
 
-        // 12. Return NormalCompletion(unused).
+        // 11. Return NormalCompletion(unused).
         return {};
     };
 

Libraries/LibWeb/HTML/Scripting/SyntheticRealmSettings.cpp

@@ -13,7 +13,6 @@ void SyntheticRealmSettings::visit_edges(JS::Cell::Visitor& visitor)
 {
     execution_context->visit_edges(visitor);
     visitor.visit(principal_realm);
-    visitor.visit(underlying_realm);
     visitor.visit(module_map);
 }
 

Libraries/LibWeb/HTML/Scripting/SyntheticRealmSettings.h

@@ -23,10 +23,6 @@ struct SyntheticRealmSettings {
     // The principal realm which this synthetic realm exists within.
     GC::Ref<JS::Realm> principal_realm;
 
-    // An underlying realm
-    // The synthetic realm which this settings object represents.
-    GC::Ref<JS::Realm> underlying_realm;
-
     // A module map
     // A module map that is used when importing JavaScript modules.
     GC::Ref<ModuleMap> module_map;