From 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Fri, 19 Apr 2024 03:47:29 +0200
Subject: Adding upstream version 115.8.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../reference/contain-baseline-ref.html            | 18 +++++++
 .../reference/contain-body-bg-001-ref.html         | 15 ++++++
 .../reference/contain-body-overflow-001-ref.html   | 15 ++++++
 .../reference/contain-body-t-o-001-ref.html        | 35 +++++++++++++
 .../reference/contain-body-w-m-001-ref.html        | 23 ++++++++
 .../reference/contain-content-011-ref.html         | 27 ++++++++++
 .../reference/contain-layout-020-ref.html          | 30 +++++++++++
 .../reference/contain-layout-021-ref.html          | 27 ++++++++++
 .../reference/contain-layout-baseline-004-ref.html | 23 ++++++++
 .../reference/contain-layout-baseline-005-ref.html | 61 ++++++++++++++++++++++
 .../reference/contain-layout-breaks-002-ref.html   | 30 +++++++++++
 .../reference/contain-layout-button-001-ref.html   | 21 ++++++++
 .../reference/contain-layout-cell-001-ref.html     | 43 +++++++++++++++
 .../reference/contain-layout-flexbox-001-ref.html  | 16 ++++++
 .../reference/contain-layout-grid-001-ref.html     | 16 ++++++
 .../reference/contain-layout-ifc-022-ref.html      | 36 +++++++++++++
 .../contain-layout-ink-overflow-013-ref.html       | 24 +++++++++
 .../contain-layout-ink-overflow-014-ref.html       | 24 +++++++++
 .../contain-layout-ink-overflow-015-ref.html       | 11 ++++
 .../contain-layout-ink-overflow-019-ref.html       | 31 +++++++++++
 .../contain-layout-ink-overflow-020-ref.html       | 20 +++++++
 .../reference/contain-layout-size-003-ref.html     | 37 +++++++++++++
 .../reference/contain-paint-001-ref.html           | 26 +++++++++
 .../reference/contain-paint-007-ref.html           | 19 +++++++
 .../reference/contain-paint-008-ref.html           | 16 ++++++
 .../reference/contain-paint-022-ref.html           | 24 +++++++++
 .../reference/contain-paint-047-ref.html           | 20 +++++++
 .../reference/contain-paint-clip-015-ref.html      | 21 ++++++++
 .../reference/contain-paint-clip-019-ref.html      | 19 +++++++
 .../reference/contain-paint-ifc-011-ref.html       | 46 ++++++++++++++++
 ...int-independent-formatting-context-001-ref.html | 14 +++++
 ...int-independent-formatting-context-003-ref.html | 14 +++++
 .../reference/contain-paint-size-001-ref.html      | 20 +++++++
 .../reference/contain-paint-size-003-ref.html      | 38 ++++++++++++++
 .../reference/contain-size-004-ref.html            | 18 +++++++
 .../reference/contain-size-005-ref.html            | 16 ++++++
 .../reference/contain-size-021-ref.html            | 31 +++++++++++
 .../reference/contain-size-022-ref.html            | 11 ++++
 .../reference/contain-size-023-ref.html            | 33 ++++++++++++
 .../reference/contain-size-025-ref.html            | 13 +++++
 .../reference/contain-size-027-ref.html            | 41 +++++++++++++++
 .../reference/contain-size-051-ref.html            | 21 ++++++++
 .../reference/contain-size-056-ref.html            | 33 ++++++++++++
 .../reference/contain-size-061-ref.html            |  9 ++++
 .../reference/contain-size-062-ref.html            | 22 ++++++++
 .../reference/contain-size-063-ref.html            |  6 +++
 .../reference/contain-size-064-ref.html            | 28 ++++++++++
 .../reference/contain-size-breaks-001-ref.html     | 31 +++++++++++
 .../reference/contain-size-button-001-ref.html     | 17 ++++++
 .../reference/contain-size-fieldset-001-ref.html   | 15 ++++++
 .../reference/contain-size-fieldset-002-ref.html   | 19 +++++++
 .../reference/contain-size-flexbox-001-ref.html    | 17 ++++++
 .../reference/contain-size-flexbox-002-ref.html    | 23 ++++++++
 .../reference/contain-size-grid-001-ref.html       | 17 ++++++
 .../reference/contain-size-grid-005-ref.html       | 49 +++++++++++++++++
 .../reference/contain-size-monolithic-001-ref.html | 21 ++++++++
 .../reference/contain-size-scrollbars-001-ref.html | 13 +++++
 .../reference/contain-size-scrollbars-004-ref.html | 25 +++++++++
 .../reference/contain-size-select-001-ref.html     | 12 +++++
 .../reference/contain-strict-011-ref.html          | 23 ++++++++
 .../reference/contain-style-breaks-001-ref.html    | 36 +++++++++++++
 .../reference/contain-style-breaks-004-ref.html    | 30 +++++++++++
 .../reference/contain-style-counters-001-ref.html  | 18 +++++++
 .../reference/contain-style-counters-003-ref.html  | 18 +++++++
 .../reference/contain-style-counters-004-ref.html  | 18 +++++++
 .../reference/contain-style-counters-005-ref.html  | 22 ++++++++
 .../contain-style-ol-ordinal-li-container-ref.html | 10 ++++
 .../contain-style-ol-ordinal-pseudo-ref.html       | 12 +++++
 ...ntain-style-ol-ordinal-pseudo-reversed-ref.html | 12 +++++
 .../reference/contain-style-ol-ordinal-ref.html    | 12 +++++
 .../contain-style-ol-ordinal-reversed-ref.html     | 12 +++++
 .../contain-style-ol-ordinal-start-ref.html        | 12 +++++
 ...ontain-style-ol-ordinal-start-reversed-ref.html | 12 +++++
 .../css-contain/reference/contain-subgrid-001.html | 35 +++++++++++++
 .../reference/counter-scoping-001-ref.html         |  9 ++++
 .../reference/counter-scoping-003-ref.html         |  9 ++++
 .../reference/pass_if_pass_below_clipped.html      | 13 +++++
 .../reference/quote-scoping-001-ref.html           |  8 +++
 .../reference/quote-scoping-002-ref.html           |  8 +++
 .../reference/quote-scoping-003-ref.html           |  8 +++
 .../quote-scoping-empty-style-boundaries-ref.html  | 12 +++++
 .../quote-scoping-invalidation-001-ref.html        |  7 +++
 .../quote-scoping-invalidation-002-ref.html        |  7 +++
 .../quote-scoping-invalidation-003-ref.html        |  7 +++
 .../quote-scoping-invalidation-004-ref.html        |  7 +++
 .../reference/ref-if-there-is-no-red.xht           | 18 +++++++
 86 files changed, 1796 insertions(+)
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-baseline-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-body-bg-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-body-overflow-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-body-t-o-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-body-w-m-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-content-011-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-020-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-021-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-004-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-005-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-breaks-002-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-button-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-cell-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-flexbox-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-grid-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-ifc-022-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-013-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-014-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-015-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-019-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-020-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-layout-size-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-007-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-008-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-022-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-047-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-015-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-019-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-ifc-011-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-size-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-paint-size-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-004-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-005-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-021-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-022-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-023-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-025-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-027-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-051-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-056-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-061-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-062-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-063-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-064-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-breaks-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-button-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-002-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-002-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-grid-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-grid-005-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-monolithic-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-004-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-size-select-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-strict-011-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-004-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-counters-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-counters-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-counters-004-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-counters-005-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-li-container-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-reversed-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-reversed-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-reversed-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/contain-subgrid-001.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/counter-scoping-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/counter-scoping-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/pass_if_pass_below_clipped.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-002-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-empty-style-boundaries-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-001-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-002-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-003-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-004-ref.html
 create mode 100644 testing/web-platform/tests/css/css-contain/reference/ref-if-there-is-no-red.xht

(limited to 'testing/web-platform/tests/css/css-contain/reference')

diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-baseline-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-baseline-ref.html
new file mode 100644
index 0000000000..1fdecb1c33
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-baseline-ref.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html lang=en>
+<meta charset=utf-8>
+<title>CSS test reference</title>
+<link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+<style>
+div {
+  display: inline-block;
+  height: 5px;
+  background: blue;
+  width: 50px;
+  color: transparent;
+  font-size: 100px;
+}
+</style>
+
+<p>Test passes if there are two, not one, blue lines below.</p>
+<div></div><div>a</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-body-bg-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-body-bg-001-ref.html
new file mode 100644
index 0000000000..1d6357e173
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-body-bg-001-ref.html
@@ -0,0 +1,15 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+html, body, p {
+    margin: 0;
+    width: 300px;
+    height: 200px;
+}
+</style>
+
+<p>Test passes if there is no red.
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-body-overflow-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-body-overflow-001-ref.html
new file mode 100644
index 0000000000..32bc8b0eaf
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-body-overflow-001-ref.html
@@ -0,0 +1,15 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test referemce</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+html, body, p, div {
+    margin: 0;
+    width: 200px;
+    height: 200px;
+}
+</style>
+
+<p>Test passes if there is no red.
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-body-t-o-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-body-t-o-001-ref.html
new file mode 100644
index 0000000000..ecf9d031a3
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-body-t-o-001-ref.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+html {
+    writing-mode: vertical-lr;
+    direction: rtl;
+    width: 100vw;
+    height: 100vh;
+    overflow: hidden;
+}
+body {
+    margin: 0;
+    border-top: 100px solid red;
+    border-bottom: 100px solid green;
+    width: 100vw;
+    height: 100vh;
+}
+div {
+    text-orientation: upright;
+}
+p {
+    margin: auto;
+    padding: 150px 0;
+    writing-mode: horizontal-tb;
+    direction: ltr;
+}
+</style>
+
+<div>
+    <p>Test passes if there is no red.
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-body-w-m-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-body-w-m-001-ref.html
new file mode 100644
index 0000000000..3341816e2b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-body-w-m-001-ref.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+html::before {
+    content: "";
+    width: 100px;
+    height: 100px;
+    background: orange;
+    display: block;
+}
+body { margin: 0; }
+p {
+    margin: 0;
+    width: 200px;
+    height: 200px;
+}
+</style>
+
+<p>Test passes if the orange square is in the upper-left corner.
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-content-011-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-content-011-ref.html
new file mode 100644
index 0000000000..00ad302ca4
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-content-011-ref.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div#green-square
+    {
+      background-color: green;
+      height: 100px;
+      width: 100px;
+    }
+
+  div#result
+    {
+      font-size: 3em;
+    }
+  </style>
+
+  <p>Test passes if there is a filled green square, no red and the number 17.
+
+  <div id="green-square"></div>
+
+  <div id="result">17</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-020-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-020-ref.html
new file mode 100644
index 0000000000..9a0eab3afe
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-020-ref.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CSS Containment Test: Removing layout containment and contained positioned elements</title>
+
+<style>
+.container {
+    width: 300px;
+    height: 300px;
+}
+.box {
+    width: 100px;
+    height: 100px;
+    background-color: green;
+}
+.fixed {
+    position: fixed;
+    top: 0;
+    left: 0;
+}
+.abspos {
+    position: absolute;
+    top: 0;
+    right: 0;
+}
+</style>
+
+<div class="container">
+  <div class="fixed box"></div>
+  <div class="abspos box"></div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-021-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-021-ref.html
new file mode 100644
index 0000000000..c29b12e137
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-021-ref.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Layout containment fixed positioned descendants</title>
+<style>
+#green {
+  background: green;
+  width: 100px;
+  height: 100px;
+}
+body {
+  height: 3000px;
+  margin: 0px;
+}
+#spacer {
+  height: 200px;
+}
+</style>
+<script>
+function runTest() {
+  document.documentElement.scrollTop += 200;
+}
+</script>
+<body onload="runTest()">
+<div id="spacer"></div>
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div id="green"></div>
+</body>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-004-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-004-ref.html
new file mode 100644
index 0000000000..69658a7004
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-004-ref.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
+<style>
+div {
+  display: inline-block;
+  font: 100px/1 Ahem;
+  width: 100px;
+  height: 100px;
+}
+#first {
+  color: blue;
+  position: relative;
+  top: 20px;
+}
+#second {
+  color: green;
+}
+</style>
+<p>Test passes if there is not a rectangle as the two boxes ("blue" and "green") are not baseline aligned.</p>
+<div id="first">X</div><div id="second">X</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-005-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-005-ref.html
new file mode 100644
index 0000000000..360652c939
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-baseline-005-ref.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+.wrapper {
+  height: 110px;
+}
+.wrapper > * {
+  vertical-align: bottom;
+  background: cyan;
+  font-size: 20px;
+}
+.wrapper > :nth-child(1) {
+  background: magenta;
+}
+.inline-block {
+  display: inline-block;
+}
+canvas {
+  width: 100px;
+  height: 100px;
+}
+fieldset, details {
+  display: inline-block;
+  width: max-content;
+}
+</style>
+<p>Test passes if it has the same output than the reference (all elements are aligned on the bottom edge).</p>
+<div class="wrapper">
+  <div class="inline-block" style="font-size: 80px;">foo</div>
+  <div class="inline-block">foo</div>
+  <div class="inline-block" style="border: solid thick; padding: 2px;">foo</div>
+  <div style="display: inline-flex;">foo</div>
+  <div style="display: inline-flex; border: solid thick; padding: 2px;">foo</div>
+  <div style="display: inline-grid;">foo</div>
+  <div style="display: inline-grid; border: solid thick; padding: 2px;">foo</div>
+</div>
+<div class="wrapper">
+  <canvas></canvas>
+  <div class="inline-block">foo</div>
+  <button>foo</button>
+  <select><option>foo</option></select>
+  <select multiple style="height: 40px;"><option>foo</option></select>
+  <textarea style="height: 40px;"></textarea>
+</div>
+<div class="wrapper">
+  <canvas></canvas>
+  <input value="foo" size="3"></input>
+  <input type="file"></input>
+</div>
+<div class="wrapper">
+  <canvas></canvas>
+  <table style="display: inline-table;"><tr><td>foo</td></tr></table>
+  <canvas></canvas>
+  <fieldset></fieldset>
+  <fieldset><legend>foo</legend></fieldset>
+  <fieldset><legend>foo</legend>foo</fieldset>
+  <details></details>
+  <details><summary>foo</summary>foo</details> <details open="true"><summary>foo</summary>foo</details>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-breaks-002-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-breaks-002-ref.html
new file mode 100644
index 0000000000..72a3beff84
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-breaks-002-ref.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      float: left;
+    }
+
+  img
+    {
+      vertical-align: top;
+    }
+  </style>
+
+  <p>Test passes if there is a) a blue square below a yellow square and b) an orange square below a blue square.
+
+  <div>
+    <img src="../support/swatch-yellow.png" width="100" height="100" alt="Image download support must be enabled">
+    <br>
+    <img src="../support/swatch-blue.png" width="100" height="100" alt="Image download support must be enabled">
+    <br>
+    <img src="../support/swatch-orange.png" width="100" height="100" alt="Image download support must be enabled">
+  </div>
+
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-button-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-button-001-ref.html
new file mode 100644
index 0000000000..da83204dce
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-button-001-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+div.fakeButton {
+  display: inline-block;
+  border: 5px solid green;
+  padding: 0;
+  margin-bottom: 2px;
+  color: transparent;
+  width: 0;
+  height: 0px;
+  /* Layout containment creates a stacking context, the following lines simuluate the same in the reference file. */
+  position: relative;
+  z-index: 1;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a 10px green square aligned 2px above the text's baseline, and then the word "after".</p>
+before<div class="fakeButton"></div>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-cell-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-cell-001-ref.html
new file mode 100644
index 0000000000..9ff7f45e39
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-cell-001-ref.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  table
+    {
+      background-color: blue;
+      border-spacing: 2px;
+      height: 206px;
+      table-layout: fixed;
+      width: 206px;
+    }
+
+  td
+    {
+      background-color: white;
+      padding: 0px;
+      vertical-align: baseline;
+    }
+
+  span
+    {
+      background-color: green;
+      color: white;
+      font-family: monospace;
+      vertical-align: top;
+    }
+  </style>
+
+  <p>Test passes if there is the word PASS and if there is <strong>no red</strong>.
+
+  <table>
+
+    <tr><td>&nbsp;<td>&nbsp;
+
+    <tr><td>&nbsp;<td><span>PASS</span>
+
+  </table>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-flexbox-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-flexbox-001-ref.html
new file mode 100644
index 0000000000..832e4c72c2
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-flexbox-001-ref.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+div {
+  display: inline-flex;
+  border: 5px solid green;
+  /* Layout containment creates a stacking context, the following lines simuluate the same in the reference file. */
+  position: relative;
+  z-index: 1;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a 10px green square at the bottom, and then the word "after".</p>
+before<div></div>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-grid-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-grid-001-ref.html
new file mode 100644
index 0000000000..b5ff8e0e0d
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-grid-001-ref.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+div {
+  display: inline-grid;
+  border: 5px solid green;
+  /* Layout containment creates a stacking context, the following lines simuluate the same in the reference file. */
+  position: relative;
+  z-index: 1;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a 10px green square at the bottom, and then the word "after".</p>
+before<div></div>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-ifc-022-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ifc-022-ref.html
new file mode 100644
index 0000000000..682af7d4f4
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ifc-022-ref.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      color: transparent;
+      float: left;
+      font-size: 16px;
+      padding: 8px;
+    }
+
+  div#blue-rectangle
+    {
+      background-color: blue;
+      margin: 8px;
+      width: 6em;
+    }
+
+  div#orange-rectangle
+    {
+      background-color: orange;
+      width: 12em;
+    }
+  </style>
+
+  <p>Test passes if the orange rectangle and blue rectangle do not overlap.
+
+  <div id="blue-rectangle">Some text in a blue rectangle.</div>
+
+  <div id="orange-rectangle">Some text in an orange rectangle. Some text in an orange rectangle. Some text in an orange rectangle.</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-013-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-013-ref.html
new file mode 100644
index 0000000000..27041414e4
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-013-ref.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      font-family: monospace;
+      font-size: 100px;
+      height: 3em;
+      overflow: scroll;
+      width: 4ch;
+    }
+  </style>
+
+ <body>
+
+  <p>Test passes if there is no red.
+
+  <div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-014-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-014-ref.html
new file mode 100644
index 0000000000..a2b75db314
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-014-ref.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      font-family: monospace;
+      font-size: 100px;
+      height: 2.8ch;
+      overflow: scroll;
+      width: 4ch;
+    }
+  </style>
+
+ <body>
+
+  <p>Test passes if there is no red.
+
+  <div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-015-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-015-ref.html
new file mode 100644
index 0000000000..8dbbbbd3ec
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-015-ref.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+ <body>
+
+  <p>Test passes if there is no red.
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-019-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-019-ref.html
new file mode 100644
index 0000000000..7ec1d1bf8e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-019-ref.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div#parent
+    {
+      height: 100px;
+      width: 100px;
+      overflow: scroll;
+    }
+
+  div#child
+    {
+      background-color: green;
+      height: 100px;
+      width: 100px;
+    }
+  </style>
+
+  <body onload="document.getElementById('parent').scrollLeft = 100; document.getElementById('parent').scrollTop = 125;">
+
+  <p>Test passes if there is a filled green square <strong>with 2 scroll bars</strong> and if there is <strong>no red</strong>.
+
+  <div id="parent">
+    <div id="child"></div>
+  </div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-020-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-020-ref.html
new file mode 100644
index 0000000000..57a4e9c361
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-ink-overflow-020-ref.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      background-color: green;
+      height: 100px;
+      width: 100px;
+    }
+  </style>
+
+  <p>Test passes if there is a filled green square, <strong>no scrollbar around it</strong> and <strong>no red</strong>.
+
+  <div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-layout-size-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-layout-size-003-ref.html
new file mode 100644
index 0000000000..e3932a9b05
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-layout-size-003-ref.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      color: transparent;
+      float: left;
+      font-size: 16px;
+      padding: 8px;
+    }
+
+  div#blue-rectangle
+    {
+      background-color: blue;
+      margin: 8px;
+      width: 6em;
+    }
+
+  div#orange-rectangle
+    {
+      background-color: orange;
+      height: 0px;
+      width: 12em;
+    }
+  </style>
+
+  <p>Test passes if the orange rectangle and blue rectangle do not overlap.
+
+  <div id="blue-rectangle">Some text in a blue rectangle.</div>
+
+  <div id="orange-rectangle">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore.</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-001-ref.html
new file mode 100644
index 0000000000..639fbb2248
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-001-ref.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test: paint containment use the padding edge</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+div {
+  width: 100px;
+  height: 100px;
+  background: blue;
+  padding: 50px;
+  border-radius: 100px;
+  overflow: hidden
+}
+div::before {
+  content:"";
+  display: block;
+  background: green;
+  width: 100px;
+  height: 100px;
+}
+</style>
+
+<p>Test passes if there is a green square in a rounded blue box, and no red.
+<div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-007-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-007-ref.html
new file mode 100644
index 0000000000..ae3c424f72
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-007-ref.html
@@ -0,0 +1,19 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+rtc {
+  display: ruby-text-container;
+  font-size: 1rem;
+}
+rtc::after {
+  content: "PASS";
+  position: absolute;
+}
+</style>
+
+<p>This test passes if you can see the word PASS below.
+<div><ruby><rtc></rtc></ruby></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-008-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-008-ref.html
new file mode 100644
index 0000000000..b94055eb1b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-008-ref.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test: paint containment on ruby-text</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+rt {
+  display: ruby-text;
+  font-size: 1rem;
+  font-family: monospace;
+}
+</style>
+
+<p>This test passes if you can see the word PASS below.
+<div><ruby><rt><span style="margin-left: 4ch;"></span>PASS</rt></ruby></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-022-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-022-ref.html
new file mode 100644
index 0000000000..b3bb7576f2
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-022-ref.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      background-color: green;
+      height: 100px;
+      left: 100px;
+      position: relative;
+      top: 100px;
+      width: 100px;
+    }
+
+  </style>
+
+  <p>Test passes if there is a filled green square and <strong>no red</strong>.
+
+  <div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-047-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-047-ref.html
new file mode 100644
index 0000000000..f13649977f
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-047-ref.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      color: green;
+      font-family: monospace;
+      font-size: 100px;
+  }
+  </style>
+
+  <p>Test passes if there is <strong>no red</strong>.
+
+  <div>PASS</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-015-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-015-ref.html
new file mode 100644
index 0000000000..781a6d2f2f
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-015-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      background-color: green;
+      border-radius: 50%;
+      height: 100px;
+      width: 100px;
+    }
+  </style>
+
+  <p>Test passes if there is a filled green circle and <strong>no red</strong>.
+
+  <div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-019-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-019-ref.html
new file mode 100644
index 0000000000..2a529c12c4
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-clip-019-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+
+<meta charset="UTF-8">
+
+<title>CSS Reference Test</title>
+
+<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+
+<style>
+  #green {
+    background-color: green;
+    width: 100px;
+    height: 100px;
+  }
+</style>
+
+<p>Test passes if there there is a green square. No red and no scrollbars should be visible.</p>
+
+<div id="green"></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-ifc-011-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-ifc-011-ref.html
new file mode 100644
index 0000000000..229c8c2d74
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-ifc-011-ref.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  p
+    {
+      margin-bottom: 30px;
+    }
+
+  div
+    {
+      height: 30px;
+    }
+
+  div.orange
+    {
+      background-color: orange;
+    }
+
+  div.blue
+    {
+      background-color: blue;
+    }
+
+  div#lime
+    {
+      background-color: lime;
+    }
+  </style>
+
+  <p>Test passes if there are 5 horizontal stripes across the page in this order (from top to bottom): an orange stripe, a blue stripe, a bright green stripe, a blue stripe and then an orange stripe.
+
+  <div class="orange"></div>
+
+  <div class="blue"></div>
+
+  <div id="lime"></div>
+
+  <div class="blue"></div>
+
+  <div class="orange"></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-001-ref.html
new file mode 100644
index 0000000000..08900b201b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-001-ref.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+.wrapper {
+  border: solid thick;
+  margin: 1em;
+}
+</style>
+<p>Test passes if it has the same output than the reference.</p>
+<div class="wrapper">
+  <div style="margin: 2em 0;">This text should have 2em top and bottom margins (margins do not collapse).</div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-003-ref.html
new file mode 100644
index 0000000000..0cef592ba5
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-independent-formatting-context-003-ref.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+.wrapper {
+  border: solid thick;
+  margin: 1em;
+}
+</style>
+<p>Test passes if it has the same output than the reference.</p>
+<div class="wrapper">
+  <div style="margin: 1em 0;">This text should have 1em top and bottom margins.</div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-size-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-size-001-ref.html
new file mode 100644
index 0000000000..9aad8a490b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-size-001-ref.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      background-color: green;
+      height: 40px;
+      width: 206px;
+    }
+  </style>
+
+  <p>Test passes if there is a short horizontal green stripe and <strong>no red</strong>.
+
+  <div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-paint-size-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-paint-size-003-ref.html
new file mode 100644
index 0000000000..27820fae76
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-paint-size-003-ref.html
@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      color: transparent;
+      float: left;
+      font-size: 16px;
+      padding: 8px;
+    }
+
+  div#blue-rectangle
+    {
+      background-color: blue;
+      margin: 8px;
+      width: 6em;
+    }
+
+  div#orange-rectangle
+    {
+      background-color: orange;
+      height: 0px;
+      overflow: hidden;
+      width: 12em;
+    }
+  </style>
+
+  <p>Test passes if the orange rectangle and blue rectangle do not overlap.
+
+  <div id="blue-rectangle">Some text in a blue rectangle.</div>
+
+  <div id="orange-rectangle">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore.</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-004-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-004-ref.html
new file mode 100644
index 0000000000..75ae2bcc2b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-004-ref.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+rtc {
+  display: ruby-text-container;
+  font-size: 1rem;
+}
+div {
+  overflow: hidden;
+}
+</style>
+
+<p>This test passes if you can see the word PASS below.
+<div><ruby><rtc>PASS</rtc></ruby></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-005-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-005-ref.html
new file mode 100644
index 0000000000..001fc90061
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-005-ref.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<style>
+div { overflow: hidden; }
+rt {
+  display: ruby-text;
+  font-size: 1rem;
+}
+</style>
+
+<p>This test passes if you can see the word PASS below.
+<div><ruby><rt>PASS</rt></ruby></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-021-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-021-ref.html
new file mode 100644
index 0000000000..639daa8437
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-021-ref.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+  div.inline-block {
+    display: inline-block;
+    height: 100px;
+    width: 100px;
+  }
+
+  div#blue-test {
+    background-color: blue;
+    padding: 50px;
+    box-sizing: border-box;
+  }
+
+  div#orange-reference {
+    background-color: orange;
+  }
+</style>
+
+<p>This test passes if the painted blue area is <strong>exactly as wide as</strong> the orange square.
+
+<div>
+  <div id="blue-test" class="inline-block"><img src="../support/blue50wBy46h.png" alt="Image download support must be enabled"></div>
+</div>
+
+<div>
+  <div id="orange-reference" class="inline-block"></div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-022-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-022-ref.html
new file mode 100644
index 0000000000..3ca9ac9ee4
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-022-ref.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <p>This test passes if the painted blue area is <strong>exactly as tall as</strong> the orange square.
+
+  <div><img src="../support/swatch-blue.png" width="100" height="100" alt="Image download support must be enabled"> <img src="../support/swatch-orange.png" width="100" height="100" alt="Image download support must be enabled"></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-023-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-023-ref.html
new file mode 100644
index 0000000000..1073100b0c
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-023-ref.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+  div.inline-block {
+    display: inline-block;
+    height: 100px;
+    width: 100px;
+  }
+
+  div#blue-test {
+    background-color: blue;
+    color: transparent;
+    font-size: 100px;
+    padding: 50px;
+    box-sizing: border-box;
+  }
+
+  div#orange-reference {
+    background-color: orange;
+  }
+</style>
+
+<p>This test passes if the painted blue area is <strong>exactly as wide as</strong> the orange square.
+
+<div>
+  <div id="blue-test" class="inline-block">B</div>
+</div>
+
+<div>
+  <div id="orange-reference" class="inline-block"></div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-025-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-025-ref.html
new file mode 100644
index 0000000000..de9cea1050
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-025-ref.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <p>This test passes if the painted blue area is <strong>exactly as wide as</strong> the orange square.
+
+  <div><img src="../support/swatch-blue.png" width="100" height="100" alt="Image download support must be enabled"></div>
+
+  <div><img src="../support/swatch-orange.png" width="100" height="100" alt="Image download support must be enabled"></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-027-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-027-ref.html
new file mode 100644
index 0000000000..ce4c699dc1
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-027-ref.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+  div.inline-block {
+    display: inline-block;
+    height: 100px;
+    width: 100px;
+  }
+
+  div#blue-test {
+    background-color: blue;
+    color: transparent;
+    font-size: 50px;
+    line-height: 1;
+    padding: 50px;
+    box-sizing: border-box;
+  }
+
+  div#orange-reference {
+    background-color: orange;
+  }
+
+  span {
+    display: block;
+  }
+</style>
+
+<p>This test passes if the painted blue area is <strong>exactly as wide as</strong> the orange square.
+
+<div>
+  <div id="blue-test" class="inline-block">
+    <span>B</span>
+    <span>L</span>
+  </div>
+</div>
+
+<div>
+  <div id="orange-reference" class="inline-block"></div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-051-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-051-ref.html
new file mode 100644
index 0000000000..07455aaed2
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-051-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  td
+    {
+      font-size: 50px;
+    }
+  </style>
+
+  <p>Test passes if "5678" (without quotes) is readable and if the digits do not overlap each other.
+
+  <table>
+    <tr>
+      <td>5<td>6<td>7<td>8
+  </table>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-056-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-056-ref.html
new file mode 100644
index 0000000000..2e73f0e42b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-056-ref.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  table
+    {
+      width: 400px;
+    }
+
+  caption
+    {
+      border-top: orange solid 6px;
+      color: blue;
+      font-size: 32px;
+    }
+
+  span
+    {
+      bottom: 3px;
+      position: relative;
+    }
+  </style>
+
+  <p>Test passes if the words "Table caption" are below a thick orange line. Test fails if, instead of a thick orange line, there is an orange rectangle with the words "Table caption" in it.
+
+  <table>
+    <caption><span>Table caption</span></caption>
+  </table>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-061-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-061-ref.html
new file mode 100644
index 0000000000..756c20d40e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-061-ref.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <p>Test passes if the word FAIL is absent.
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-062-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-062-ref.html
new file mode 100644
index 0000000000..dbfa77f6ac
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-062-ref.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      border: orange solid 3px;
+      color: blue;
+      font-size: 32px;
+      height: 0px;
+      width: 400px;
+    }
+  </style>
+
+  <p>Test passes if the words "Text sample" are below a thick orange line. Test fails if, instead of a thick orange line, there is an orange rectangle with the words "Text sample" in it.
+
+  <div>Text sample</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-063-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-063-ref.html
new file mode 100644
index 0000000000..9544ebcac2
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-063-ref.html
@@ -0,0 +1,6 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>Test reference</title>
+<link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<p>Test passes if there is no red below.
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-064-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-064-ref.html
new file mode 100644
index 0000000000..6d2876ae9b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-064-ref.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+<style>
+div { font-size: 50px; }
+.green { background: green; }
+.grid {
+    display: grid;
+    grid-template-columns: min-content max-content;
+}
+</style>
+
+<p>This test passes if there are two green rectangles and no red.
+
+<div class=grid>
+    <div style="grid-area: 1/1">&nbsp;</div>
+    <div style="grid-area: 2/2"id=test class="grid">
+        <div>&nbsp;</div>
+        <div class=green></div>
+        <div class=green></div>
+        <div>&nbsp;</div>
+    </div>
+</div>
+
+
+
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-breaks-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-breaks-001-ref.html
new file mode 100644
index 0000000000..b807ea5a11
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-breaks-001-ref.html
@@ -0,0 +1,31 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+  <meta name=flags content="ahem">
+
+<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
+<style>
+article {
+  height: 2.5em;
+  column-gap: 0;
+  columns: 3 1em;
+  width: 3em;
+  column-fill: auto;
+
+  font-size: 40px;
+  font-family: ahem;
+  line-height: 1;
+}
+div {
+  background: orange;
+  padding-top: 5em;
+}
+</style>
+
+<p>This test passes if there is an orange rectangle below. If the shape is not a rectangle, the test fails.
+
+<article>
+<div></div>
+</article>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-button-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-button-001-ref.html
new file mode 100644
index 0000000000..eff64aa8e2
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-button-001-ref.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+button {
+  border: 5px solid green;
+  padding: 0;
+  color: transparent;
+  width: 0;
+  height: 0;
+  font-size: 2em;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a 10px green square at the top, and then the word "after".</p>
+before<button>b</button>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-001-ref.html
new file mode 100644
index 0000000000..85f5c73c2e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-001-ref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+fieldset {
+  display: inline-block;
+  color: transparent;
+  border: none;
+  padding: 0;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a small space, and then the word "after".</p>
+before<fieldset></fieldset>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-002-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-002-ref.html
new file mode 100644
index 0000000000..51ff6998b6
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-fieldset-002-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+<style>
+#border {
+  border: 1px solid black;
+  width: min-content;
+}
+fieldset {
+  visibility: hidden;
+  height: 1px;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You should see a black border box below.</p>
+<div id="border">
+  <fieldset></fieldset>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-001-ref.html
new file mode 100644
index 0000000000..70f4086430
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-001-ref.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+div {
+  display: inline-flex;
+  border: 5px solid green;
+  color: transparent;
+  width: 0;
+  height: 0;
+  font-size: 2em;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a 10px green square at the top, and then the word "after".</p>
+before<div>f</div>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-002-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-002-ref.html
new file mode 100644
index 0000000000..a75fa26c9f
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-flexbox-002-ref.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<title>Tests that scrollbars are handled correctly in a flex item with contains:size</title>
+<link rel="author" title="Google LLC" href="https://www.google.com">
+
+<style>
+div > div {
+  vertical-align: top;
+  display: inline-block;
+  contain: size;
+  overflow: scroll;
+  border: 1px solid;
+}
+</style>
+
+<p>Test passes if the two lines below look the same.</p>
+
+<div style="line-height: 1.0;">
+  <div></div>
+</div>
+
+<div style="line-height: 1.0;">
+  <div></div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-grid-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-grid-001-ref.html
new file mode 100644
index 0000000000..cf4f807665
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-grid-001-ref.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+div {
+  display: inline-grid;
+  border: 5px solid green;
+  color: transparent;
+  width: 0;
+  height: 0;
+  font-size: 2em;
+}
+</style>
+
+<p>This test passes if it has the same output as the reference. You see the word "before", a 10px green square at the top, and then the word "after".</p>
+before<div>g</div>after
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-grid-005-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-grid-005-ref.html
new file mode 100644
index 0000000000..b2fdf4b887
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-grid-005-ref.html
@@ -0,0 +1,49 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>CSS Reftest Reference</title>
+  <link rel="author" title="Gerald Squelart" href="mailto:gsquelart@mozilla.com">
+  <style>
+  .basic {
+    display: grid;
+    border: 1em solid green;
+  }
+  .height-ref {
+    height: 40px;
+    background: lightblue;
+  }
+  .width-ref {
+    width: 40px;
+  }
+  .floatLBasic-ref {
+    float: left;
+  }
+  .floatLWidth-ref {
+    float: left;
+    width: 40px;
+  }
+  </style>
+</head>
+<body>
+  <div class="basic"></div>
+  <br>
+
+  <div class="basic height-ref"></div>
+  <br>
+
+  <div class="basic height-ref"></div>
+  <br>
+
+  <div class="basic width-ref"></div>
+  <br>
+
+  <div class="basic width-ref"></div>
+  <br>
+
+  <div class="basic floatLBasic-ref"></div>
+  <br>
+
+  <div class="basic floatLWidth-ref"></div>
+</body>
+</html>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-monolithic-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-monolithic-001-ref.html
new file mode 100644
index 0000000000..2e8f1ba70a
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-monolithic-001-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      font-family: monospace;
+      font-size: 20px;
+      width: 8ch;
+    }
+  </style>
+
+  <p>Test passes if "AB", "CD", "EF" and "GH" are vertically aligned into 1 single column and if there is <strong>no red</strong>.
+
+
+  <div>AB<br>CD<br>EF<br>GH</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-001-ref.html
new file mode 100644
index 0000000000..402ff6c95e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-001-ref.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+div {
+  display: inline-block;
+  border: solid thick;
+  overflow: scroll;
+}
+</style>
+<p>This test passes if it has the same output as the reference.</p>
+<div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-004-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-004-ref.html
new file mode 100644
index 0000000000..91d9e51709
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-scrollbars-004-ref.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+<style>
+#scroller {
+  background: lightgreen;
+  overflow: scroll;
+  padding-bottom: 50px;
+  width: 100px;
+  height: 100px;
+}
+#content {
+  background: lightblue;
+  width: 50px;
+  height: 130px;
+}
+</style>
+
+<div id=scroller>
+  <div id=content>
+  </div>
+</div>
+
+<p>This test passes if it has the same output as the reference.</p>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-size-select-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-size-select-001-ref.html
new file mode 100644
index 0000000000..1944e49375
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-size-select-001-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Containment Test: Reference file</title>
+<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
+<style>
+select {
+  color: transparent;
+  background: white;
+}
+</style>
+<p>Test passes if it has the same output than the reference.</p>
+<select></select>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-strict-011-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-strict-011-ref.html
new file mode 100644
index 0000000000..401275b552
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-strict-011-ref.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  p
+    {
+      margin-top: 1.5em;
+    }
+
+  div
+    {
+      font-size: 3em;
+    }
+  </style>
+
+  <p>Test passes if there is the number 17.
+
+  <div>17</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-001-ref.html
new file mode 100644
index 0000000000..2c0b758e6b
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-001-ref.html
@@ -0,0 +1,36 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+<style>
+article {
+  columns: 2 1ch;
+  column-gap: 0;
+  float: left;
+  font-family: monospace;
+  margin-right: 3em;
+}
+div {
+  page-break-inside: avoid;
+  break-inside: avoid;
+}
+</style>
+
+<p>Test passes if there are two identical blocks “A” letters below.
+<article>
+  <div>
+  A<br>
+  A<br>
+  A<br>
+  A
+  <div>
+</article>
+<article>
+  <div>
+  A<br>
+  A<br>
+  A<br>
+  A
+  <div>
+</article>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-004-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-004-ref.html
new file mode 100644
index 0000000000..eaf4d566a2
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-breaks-004-ref.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+<style>
+article {
+  columns: 2 1ch;
+  column-gap: 0;
+  float: left;
+  font-family: monospace;
+  margin-right: 3em;
+  line-height: 1;
+  height: 4em;
+  column-fill: auto;
+}
+div:last-of-type {
+  break-before: column;
+}
+</style>
+
+<p>Test passes if there are two identical blocks “A” letters below.
+<article>
+  <div>A<br>A</div>
+  <div>A<br>A</div>
+</article>
+<article>
+  <div>A<br>A</div>
+  <div>A<br>A</div>
+</article>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-001-ref.html
new file mode 100644
index 0000000000..c0c652b335
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-001-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      font-size: 3em;
+    }
+  </style>
+
+  <p>Test passes if there is the digit 5.
+
+  <div>5</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-003-ref.html
new file mode 100644
index 0000000000..12f9b989fd
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-003-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
+
+  <style>
+  div
+    {
+      font-size: 3em;
+    }
+  </style>
+
+  <p>Test passes if there is the number 20.
+
+  <div>20</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-004-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-004-ref.html
new file mode 100644
index 0000000000..afe60666c0
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-004-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+
+  <meta charset="UTF-8">
+
+  <title>CSS Reference Test</title>
+
+  <link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
+
+  <style>
+  div
+    {
+      font-size: 3em;
+    }
+  </style>
+
+  <p>Test passes if there is the number 0.
+
+  <div>0</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-005-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-005-ref.html
new file mode 100644
index 0000000000..1ea1ae3f08
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-counters-005-ref.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<style>
+.contain {
+    float: right;
+    clear: both;
+}
+.reset { counter-reset: c;}
+.increment:before { content: counters(c, ""); }
+.increment { counter-increment: c; }
+</style>
+<body>
+<div>1</div>
+<div class="contain">
+    <div>1</div>
+    <div>1</div>
+</div>
+<div>2</div>
+<div class="contain">
+    <div>1</div>
+    <div>2</div>
+</div>
+<div>3</div>
\ No newline at end of file
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-li-container-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-li-container-ref.html
new file mode 100644
index 0000000000..e6c721ac2d
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-li-container-ref.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (li container, ref)</title>
+<ol>
+  <li value="1">A</li>
+  <li value="2">B</li>
+  <li value="3">X</li>
+  <li value="4">Y</li>
+  <li value="5">C</li>
+  <li value="6">D</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-ref.html
new file mode 100644
index 0000000000..5b8e4d338c
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (pseudo, ref)</title>
+<ol>
+  <li value="10">10A10</li>
+  <li value="11">11B11</li>
+  <div>
+    <li value="1">1X1</li>
+    <li value="2">2Y2</li>
+  </div>
+  <li value="12">12C12</li>
+  <li value="13">13D13</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-reversed-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-reversed-ref.html
new file mode 100644
index 0000000000..04cc67139a
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-pseudo-reversed-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (pseudo, reversed, ref)</title>
+<ol>
+  <li value="10">10A10</li>
+  <li value="9">9B9</li>
+  <div>
+    <li value="1">1X1</li>
+    <li value="2">2Y2</li>
+  </div>
+  <li value="8">8C8</li>
+  <li value="7">7D7</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-ref.html
new file mode 100644
index 0000000000..bee7deda2f
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (ref)</title>
+<ol>
+  <li value="1">A</li>
+  <li value="2">B</li>
+  <div>
+    <li value="1">X</li>
+    <li value="2">Y</li>
+  </div>
+  <li value="3">C</li>
+  <li value="4">D</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-reversed-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-reversed-ref.html
new file mode 100644
index 0000000000..bb7531790e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-reversed-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (reversed, ref)</title>
+<ol>
+  <li value="4">A</li>
+  <li value="3">B</li>
+  <div>
+    <li value="1">X</li>
+    <li value="2">Y</li>
+  </div>
+  <li value="2">C</li>
+  <li value="1">D</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-ref.html
new file mode 100644
index 0000000000..93411804b1
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (start attribute, ref)</title>
+<ol>
+  <li value="10">A</li>
+  <li value="11">B</li>
+  <div>
+    <li value="1">X</li>
+    <li value="2">Y</li>
+  </div>
+  <li value="12">C</li>
+  <li value="13">D</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-reversed-ref.html b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-reversed-ref.html
new file mode 100644
index 0000000000..60aefdf563
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-style-ol-ordinal-start-reversed-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<title>CSS Containment: contain:style and &lt;ol&gt; ordinals (start attribute, reversed, ref)</title>
+<ol>
+  <li value="10">A</li>
+  <li value="9">B</li>
+  <div>
+    <li value="1">X</li>
+    <li value="2">Y</li>
+  </div>
+  <li value="8">C</li>
+  <li value="7">D</li>
+</ol>
diff --git a/testing/web-platform/tests/css/css-contain/reference/contain-subgrid-001.html b/testing/web-platform/tests/css/css-contain/reference/contain-subgrid-001.html
new file mode 100644
index 0000000000..ab0d1fede5
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/contain-subgrid-001.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain reference: layout/paint containment on subgrid</title>
+  <link rel="author" title="Mats Palmgren" href="mailto:mats@mozilla.com">
+
+<style>
+.grid {
+  display: grid;
+  width: 40px;
+  height: 40px;
+  grid: [a] repeat(2,15px) [b] / [a] repeat(2,15px) [b];
+  gap: 10px;
+}
+
+.subgrid {
+  display: grid;
+  grid: none;
+  background: lightgrey;
+  grid-area:1/1/3/3;
+}
+
+.layout { contain: layout; }
+.paint { contain: paint; }
+
+.inner {
+  background: blue;
+  grid-area:a/a/b/b;
+}
+</style>
+
+<div class="grid"><div class="subgrid layout"><div class="inner"></div></div></div>
+<div class="grid"><div class="subgrid paint"><div class="inner"></div></div></div>
+<div class="grid"><div class="subgrid layout"><div class="inner"></div></div></div>
+<div class="grid"><div class="subgrid paint"><div class="inner"></div></div></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/counter-scoping-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/counter-scoping-001-ref.html
new file mode 100644
index 0000000000..2ebbb9a93c
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/counter-scoping-001-ref.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<p>Test passes if the text below is "1 1.2" (not including the quotation marks).<p>
+<div>1 1.2</div>
+
diff --git a/testing/web-platform/tests/css/css-contain/reference/counter-scoping-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/counter-scoping-003-ref.html
new file mode 100644
index 0000000000..49e7b85e87
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/counter-scoping-003-ref.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<p>Test passes if the text below is "1 2" (not including the quotation marks).<p>
+<div>1 2</div>
+
diff --git a/testing/web-platform/tests/css/css-contain/reference/pass_if_pass_below_clipped.html b/testing/web-platform/tests/css/css-contain/reference/pass_if_pass_below_clipped.html
new file mode 100644
index 0000000000..044783d1e5
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/pass_if_pass_below_clipped.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<html>
+<head>
+   <title>Reference rendering - passes if there is the word "PASS" below</title>
+<style>
+div { overflow: hidden; }
+</style>
+</head>
+<body>
+   <p>Test passes if there is the word "PASS" below.</p>
+   <div>PASS</div>
+</body>
+</html>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-001-ref.html
new file mode 100644
index 0000000000..0b0e9c467a
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-001-ref.html
@@ -0,0 +1,8 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+<p>Test passes if the text below is "A1Z" (not including the quotation marks).<p>
+<div>A1Z</div>
+
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-002-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-002-ref.html
new file mode 100644
index 0000000000..c7239e3f48
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-002-ref.html
@@ -0,0 +1,8 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<p>Test passes if the text below is "AZZ" (not including the quotation marks).<p>
+<div>AZZ</span></div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-003-ref.html
new file mode 100644
index 0000000000..2bc8d6730e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-003-ref.html
@@ -0,0 +1,8 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test reference</title>
+  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">
+
+<p>Test passes if the text below is "AZ" (not including the quotation marks).<p>
+<div>AZ</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-empty-style-boundaries-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-empty-style-boundaries-ref.html
new file mode 100644
index 0000000000..6437e08eb1
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-empty-style-boundaries-ref.html
@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang=en>
+  <meta charset=utf-8>
+  <title>CSS-contain test: nested style containment and the quote element following a style boundary without any quotes</title>
+  <link rel="author" title="Martin Robinson" href="mailto:mrobinson@igalia.com">
+  <link rel=help href="https://drafts.csswg.org/css-contain-1/#containment-style">
+
+<div>
+    <div>
+        <q></q>
+    </div>
+</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-001-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-001-ref.html
new file mode 100644
index 0000000000..5c1a6203e6
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-001-ref.html
@@ -0,0 +1,7 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS-contain test reference: style containment dynamic containment set invalidation</title>
+<link rel="author" title="Daniil Sakhapov" href="sakhapov@google.com">
+
+<p>Test passes if the text below is "A1(19" (not including the quotation marks).<p>
+<div>A<div>1 (</div>1 9</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-002-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-002-ref.html
new file mode 100644
index 0000000000..e48a080e92
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-002-ref.html
@@ -0,0 +1,7 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS-contain test reference: style containment dynamic containment set unset invalidation</title>
+<link rel="author" title="Daniil Sakhapov" href="sakhapov@google.com">
+
+<p>Test passes if the text below is "A1(+-" (not including the quotation marks).<p>
+<div>A<div>1 (</div>+ -</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-003-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-003-ref.html
new file mode 100644
index 0000000000..766ad6cbe9
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-003-ref.html
@@ -0,0 +1,7 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS-contain test reference: style containment dynamic containment set unset set invalidation</title>
+<link rel="author" title="Daniil Sakhapov" href="sakhapov@google.com">
+
+<p>Test passes if the text below is "A119" (not including the quotation marks).<p>
+<div>A<div>1</div>1 9</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-004-ref.html b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-004-ref.html
new file mode 100644
index 0000000000..8280075f00
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/quote-scoping-invalidation-004-ref.html
@@ -0,0 +1,7 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS-contain test reference: style containment invalidation with elements in different subtrees</title>
+<link rel="author" title="Daniil Sakhapov" href="sakhapov@google.com">
+
+<p>Test passes if the text below is "A111119" (not including the quotation marks).<p>
+<div>A<div>1 1</div><div>1 1</div>1 9</div>
diff --git a/testing/web-platform/tests/css/css-contain/reference/ref-if-there-is-no-red.xht b/testing/web-platform/tests/css/css-contain/reference/ref-if-there-is-no-red.xht
new file mode 100644
index 0000000000..a5b4e9f47a
--- /dev/null
+++ b/testing/web-platform/tests/css/css-contain/reference/ref-if-there-is-no-red.xht
@@ -0,0 +1,18 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+
+<html xmlns="http://www.w3.org/1999/xhtml">
+
+ <head>
+
+  <title>CSS Reftest Reference</title>
+
+  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" />
+
+ </head>
+
+ <body>
+
+  <p>Test passes if there is <strong>no red</strong>.</p>
+
+ </body>
+</html>
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