diff --git a/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/name-attribute.tentative.html b/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/name-attribute.tentative.html
index 2276b2d36d61b..22cecfe4dc018 100644
--- a/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/name-attribute.tentative.html
+++ b/testing/web-platform/tests/html/semantics/interactive-elements/the-details-element/name-attribute.tentative.html
@@ -1004,133 +1004,6 @@
 "
 )
 ;
-/
-/
-The
-next
-two
-tests
-test
-characteristics
-of
-the
-design
-that
-are
-only
-/
-/
-exposed
-via
-mutation
-events
-.
-If
-mutation
-events
-(
-for
-attribute
-/
-/
-addition
-/
-removal
-)
-are
-removed
-from
-the
-web
-these
-tests
-could
-be
-/
-/
-removed
-and
-some
-small
-simplifications
-could
-be
-made
-to
-the
-code
-/
-/
-implementing
-this
-feature
-.
-function
-mutation_events_for_attribute_removal_supported
-(
-)
-{
-container
-.
-innerHTML
-=
-<
-div
-id
-=
-"
-event
--
-removal
--
-test
-"
->
-<
-/
-div
->
-;
-let
-element
-=
-container
-.
-firstChild
-;
-let
-event_fired
-=
-false
-;
-element
-.
-addEventListener
-(
-"
-DOMSubtreeModified
-"
-event
-=
->
-event_fired
-=
-true
-)
-;
-element
-.
-removeAttribute
-(
-"
-id
-"
-)
-;
-return
-event_fired
-;
-}
 promise_test
 (
 async
@@ -1138,17 +1011,6 @@
 =
 >
 {
-if
-(
-!
-mutation_events_for_attribute_removal_supported
-(
-)
-)
-{
-return
-;
-}
 container
 .
 innerHTML
@@ -1284,13 +1146,13 @@
 )
 ;
 let
-received_ids
+mutation_event_received_ids
 =
 [
 ]
 ;
 let
-listener
+mutation_listener
 =
 event
 =
@@ -1335,7 +1197,7 @@
 "
 )
 ;
-received_ids
+mutation_event_received_ids
 .
 push
 (
@@ -1346,6 +1208,18 @@
 ;
 }
 ;
+let
+toggle_event_received_ids
+=
+[
+]
+;
+let
+toggle_event_promises
+=
+[
+]
+;
 for
 (
 let
@@ -1361,13 +1235,77 @@
 "
 DOMSubtreeModified
 "
-listener
+mutation_listener
+)
+;
+toggle_event_promises
+.
+push
+(
+new
+Promise
+(
+(
+resolve
+reject
+)
+=
+>
+{
+element
+.
+addEventListener
+(
+"
+toggle
+"
+event
+=
+>
+{
+assert_equals
+(
+event
+.
+type
+"
+toggle
+"
+)
+;
+assert_equals
+(
+event
+.
+target
+element
+)
+;
+toggle_event_received_ids
+.
+push
+(
+element
+.
+id
+)
+;
+resolve
+(
+undefined
+)
+;
+}
+)
+;
+}
+)
 )
 ;
 }
 assert_array_equals
 (
-received_ids
+mutation_event_received_ids
 [
 ]
 )
@@ -1397,9 +1335,31 @@
 =
 true
 ;
+if
+(
+mutation_event_received_ids
+.
+length
+=
+=
+0
+)
+{
+/
+/
+ok
+if
+mutation
+events
+are
+not
+supported
+}
+else
+{
 assert_array_equals
 (
-received_ids
+mutation_event_received_ids
 [
 "
 e0
@@ -1429,6 +1389,7 @@
 "
 )
 ;
+}
 assert_element_states
 (
 elements
@@ -1445,10 +1406,63 @@
 "
 )
 ;
+assert_array_equals
+(
+toggle_event_received_ids
+[
+]
+"
+toggle
+events
+received
+before
+awaiting
+promises
+"
+)
+;
+await
+Promise
+.
+all
+(
+toggle_event_promises
+)
+;
+assert_array_equals
+(
+toggle_event_received_ids
+[
+"
+e1
+"
+"
+e0
+"
+"
+e3
+"
+"
+e2
+"
+]
+"
+toggle
+events
+received
+after
+awaiting
+promises
+"
+)
+;
 }
 "
 mutation
 event
+and
+toggle
+event
 order
 matches
 order
@@ -1462,6 +1476,139 @@
 "
 )
 ;
+/
+/
+This
+function
+is
+used
+to
+guard
+tests
+that
+test
+behavior
+that
+is
+/
+/
+relevant
+only
+because
+of
+Mutation
+Events
+.
+If
+mutation
+events
+(
+for
+/
+/
+attribute
+addition
+/
+removal
+)
+are
+removed
+from
+the
+web
+the
+tests
+using
+/
+/
+this
+function
+can
+be
+removed
+.
+function
+mutation_events_for_attribute_removal_supported
+(
+)
+{
+if
+(
+!
+(
+"
+MutationEvent
+"
+in
+window
+)
+)
+{
+return
+false
+;
+}
+container
+.
+innerHTML
+=
+<
+div
+id
+=
+"
+event
+-
+removal
+-
+test
+"
+>
+<
+/
+div
+>
+;
+let
+element
+=
+container
+.
+firstChild
+;
+let
+event_fired
+=
+false
+;
+element
+.
+addEventListener
+(
+"
+DOMSubtreeModified
+"
+event
+=
+>
+event_fired
+=
+true
+)
+;
+element
+.
+removeAttribute
+(
+"
+id
+"
+)
+;
+return
+event_fired
+;
+}
 promise_test
 (
 async