diff --git a/testing/web-platform/tests/css/css-flexbox/percentage-heights-010.html b/testing/web-platform/tests/css/css-flexbox/percentage-heights-010.html
new file mode 100644
index 0000000000000..8cc7819b21b17
--- /dev/null
+++ b/testing/web-platform/tests/css/css-flexbox/percentage-heights-010.html
@@ -0,0 +1,239 @@
+<
+!
+DOCTYPE
+html
+>
+<
+title
+>
+A
+height
+:
+100
+%
+descendant
+should
+trigger
+a
+relayout
+when
+stretching
+.
+<
+/
+title
+>
+<
+link
+rel
+=
+"
+help
+"
+href
+=
+"
+https
+:
+/
+/
+drafts
+.
+csswg
+.
+org
+/
+css
+-
+flexbox
+-
+1
+/
+#
+definite
+-
+sizes
+"
+/
+>
+<
+link
+rel
+=
+"
+help
+"
+href
+=
+"
+https
+:
+/
+/
+bugs
+.
+chromium
+.
+org
+/
+p
+/
+chromium
+/
+issues
+/
+detail
+?
+id
+=
+1043071
+"
+/
+>
+<
+link
+rel
+=
+"
+match
+"
+href
+=
+"
+.
+.
+/
+reference
+/
+ref
+-
+filled
+-
+green
+-
+100px
+-
+square
+.
+xht
+"
+/
+>
+<
+p
+>
+Test
+passes
+if
+there
+is
+a
+filled
+green
+square
+and
+<
+strong
+>
+no
+red
+<
+/
+strong
+>
+.
+<
+/
+p
+>
+<
+div
+style
+=
+"
+display
+:
+flex
+;
+width
+:
+100px
+;
+"
+>
+<
+div
+style
+=
+"
+display
+:
+flex
+;
+flex
+-
+direction
+:
+column
+;
+flex
+:
+1
+;
+min
+-
+height
+:
+100px
+;
+"
+>
+<
+div
+style
+=
+"
+flex
+:
+1
+;
+background
+:
+red
+;
+"
+>
+<
+div
+style
+=
+"
+height
+:
+100
+%
+;
+background
+-
+color
+:
+green
+;
+"
+>
+<
+/
+div
+>
+<
+/
+div
+>
+<
+/
+div
+>
+<
+/
+div
+>
diff --git a/testing/web-platform/tests/intersection-observer/document-scrolling-element-root.html b/testing/web-platform/tests/intersection-observer/document-scrolling-element-root.html
index af30aa5b2c32a..c36123268db8a 100644
--- a/testing/web-platform/tests/intersection-observer/document-scrolling-element-root.html
+++ b/testing/web-platform/tests/intersection-observer/document-scrolling-element-root.html
@@ -205,27 +205,6 @@
 "
 )
 ;
-root
-=
-iframe
-.
-contentDocument
-.
-scrollingElement
-;
-assert_true
-(
-!
-!
-root
-"
-Root
-element
-exists
-.
-"
-)
-;
 target
 =
 iframe
@@ -275,7 +254,9 @@
 {
 root
 :
-root
+iframe
+.
+contentDocument
 }
 )
 ;
@@ -333,10 +314,6 @@
 is
 the
 document
-'
-s
-scrolling
-element
 .
 "
 )