diff --git a/layout/reftests/mathml/reftest.list b/layout/reftests/mathml/reftest.list
deleted file mode 100644
index 0606464b18620..0000000000000
--- a/layout/reftests/mathml/reftest.list
+++ /dev/null
@@ -1,24 +0,0 @@
-# WARNING: This directory was used for MathML reftests and is only preserved for
-# the ones that cannot be rewritten as web-platform-tests.
-# If you want to add new tests for MathML, please instead consider adding them
-# to `testing/web-platform/tests/mathml` (for MathML Core tests) or to
-# `testing/web-platform/mozilla/tests/mathml/` (for Gecko-specific tests).
-
-# radicalbar*.html tests rely on reftest-zoom to verify the visibility of the
-# radical bar at different zoom levels. There does not seem to be any equivalent
-# way of testing that via WPT. See bug 1850661.
-!= radicalbar-1.html about:blank
-!= radicalbar-1a.html about:blank
-!= radicalbar-1b.html about:blank
-!= radicalbar-1c.html about:blank
-!= radicalbar-1d.html about:blank
-!= radicalbar-2.html about:blank
-!= radicalbar-2a.html about:blank
-!= radicalbar-2b.html about:blank
-!= radicalbar-2c.html about:blank
-!= radicalbar-2d.html about:blank
-!= radicalbar-3.html about:blank
-!= radicalbar-3a.html about:blank
-!= radicalbar-3b.html about:blank
-!= radicalbar-3c.html about:blank
-!= radicalbar-3d.html about:blank
diff --git a/layout/reftests/reftest.list b/layout/reftests/reftest.list
index 9bdd99e75be89..9587c70798945 100644
--- a/layout/reftests/reftest.list
+++ b/layout/reftests/reftest.list
@@ -252,9 +252,6 @@ include line-breaking/reftest.list
 # list-item/
 include list-item/reftest.list
 
-# mathml/
-include mathml/reftest.list
-
 # margin-collapsing
 include margin-collapsing/reftest.list
 
diff --git a/testing/web-platform/mozilla/meta/infrastructure/reftest-zoom/clamp-full-zoom-001.html.ini b/testing/web-platform/mozilla/meta/infrastructure/reftest-zoom/clamp-full-zoom-001.html.ini
new file mode 100644
index 0000000000000..961d8f37f4657
--- /dev/null
+++ b/testing/web-platform/mozilla/meta/infrastructure/reftest-zoom/clamp-full-zoom-001.html.ini
@@ -0,0 +1,2 @@
+[clamp-full-zoom-001.html]
+  prefs: [zoom.minPercent:50]
diff --git a/testing/web-platform/mozilla/meta/infrastructure/reftest-zoom/clamp-full-zoom-002.html.ini b/testing/web-platform/mozilla/meta/infrastructure/reftest-zoom/clamp-full-zoom-002.html.ini
new file mode 100644
index 0000000000000..fa35bd6413282
--- /dev/null
+++ b/testing/web-platform/mozilla/meta/infrastructure/reftest-zoom/clamp-full-zoom-002.html.ini
@@ -0,0 +1,2 @@
+[clamp-full-zoom-002.html]
+  prefs: [zoom.maxPercent:200]
diff --git a/testing/web-platform/mozilla/tests/common/reftest-zoom.js b/testing/web-platform/mozilla/tests/common/reftest-zoom.js
new file mode 100644
index 0000000000000..a20f2cc800ad7
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/common/reftest-zoom.js
@@ -0,0 +1,29 @@
+// This JS file allows to emulate reftest-zoom.
+// See https://firefox-source-docs.mozilla.org/layout/Reftest.html#zoom-tests-reftest-zoom-float
+
+// Retrieve reftest-zoom attribute.
+const reftestZoom = "reftest-zoom";
+const root = document.documentElement;
+if (!root.hasAttribute(reftestZoom)) {
+  throw new Error(`${reftestZoom} attribute not found on the root element.`);
+}
+
+// Parse reftest-zoom value.
+let zoom = parseFloat(root.getAttribute(reftestZoom));
+if (Number.isNaN(zoom)) {
+  throw new Error(`${reftestZoom} is not a float number.`);
+}
+
+// Clamp reftest-zoom value.
+let minZoom = SpecialPowers.getIntPref("zoom.minPercent") / 100;
+let maxZoom = SpecialPowers.getIntPref("zoom.maxPercent") / 100;
+zoom = Math.min(Math.max(zoom, minZoom), maxZoom);
+
+// Ensure the original zoom level is restored after the screenshot.
+const originalZoom = SpecialPowers.getFullZoom(window);
+window.addEventListener("beforeunload", () => {
+  SpecialPowers.setFullZoom(window, originalZoom);
+});
+
+// Set the zoom level to the specified value.
+SpecialPowers.setFullZoom(window, zoom);
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-001-ref.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-001-ref.html
new file mode 100644
index 0000000000000..1b394e0d4f2d1
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-001-ref.html
@@ -0,0 +1,4 @@
+<!DOCTYPE html>
+<html style="zoom: .5">
+  <div style="width: 500px; height: 500px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-001.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-001.html
new file mode 100644
index 0000000000000..83fc95510f2ed
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-001.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html reftest-zoom="0">
+  <link rel="help" href="https://firefox-source-docs.mozilla.org/layout/Reftest.html#zoom-tests-reftest-zoom-float"/>
+  <link rel="match" href="clamp-full-zoom-001-ref.html"/>
+  <!-- zoom.minPercent is set to 50 in the corresponding ini file. -->
+  <meta name="assert" content="Zoom is at least by zoom.minPercent."/>
+  <script src="/_mozilla/common/reftest-zoom.js"></script>
+  <div style="width: 500px; height: 500px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-002-ref.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-002-ref.html
new file mode 100644
index 0000000000000..e2dd42fc86f30
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-002-ref.html
@@ -0,0 +1,4 @@
+<!DOCTYPE html>
+<html style="zoom: 2">
+  <div style="width: 250px; height: 250px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-002.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-002.html
new file mode 100644
index 0000000000000..4fbe7edca1996
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/clamp-full-zoom-002.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html reftest-zoom="10">
+  <link rel="help" href="https://firefox-source-docs.mozilla.org/layout/Reftest.html#zoom-tests-reftest-zoom-float"/>
+  <link rel="match" href="clamp-full-zoom-002-ref.html"/>
+  <!-- zoom.maxPercent is set to 200 in the corresponding ini file. -->
+  <meta name="assert" content="Zoom is at most by zoom.maxPercent."/>
+  <script src="/_mozilla/common/reftest-zoom.js"></script>
+  <div style="width: 250px; height: 250px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-001-ref.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-001-ref.html
new file mode 100644
index 0000000000000..1b394e0d4f2d1
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-001-ref.html
@@ -0,0 +1,4 @@
+<!DOCTYPE html>
+<html style="zoom: .5">
+  <div style="width: 500px; height: 500px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-001.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-001.html
new file mode 100644
index 0000000000000..15c07de20d8b8
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-001.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<html reftest-zoom=".5">
+  <link rel="help" href="https://firefox-source-docs.mozilla.org/layout/Reftest.html#zoom-tests-reftest-zoom-float"/>
+  <link rel="match" href="set-full-zoom-001-ref.html"/>
+  <meta name="assert" content="Zoom less than one scales down the rect."/>
+  <script src="/_mozilla/common/reftest-zoom.js"></script>
+  <div style="width: 500px; height: 500px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-002-ref.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-002-ref.html
new file mode 100644
index 0000000000000..e2dd42fc86f30
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-002-ref.html
@@ -0,0 +1,4 @@
+<!DOCTYPE html>
+<html style="zoom: 2">
+  <div style="width: 250px; height: 250px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-002.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-002.html
new file mode 100644
index 0000000000000..f5d5e6a777672
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-002.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<html reftest-zoom="2">
+  <link rel="help" href="https://firefox-source-docs.mozilla.org/layout/Reftest.html#zoom-tests-reftest-zoom-float"/>
+  <link rel="match" href="set-full-zoom-002-ref.html"/>
+  <meta name="assert" content="Zoom more than one scales up the rect."/>
+  <script src="/_mozilla/common/reftest-zoom.js"></script>
+  <div style="width: 250px; height: 250px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-003-ref.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-003-ref.html
new file mode 100644
index 0000000000000..ab500f2a2e7d2
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-003-ref.html
@@ -0,0 +1,4 @@
+<!DOCTYPE html>
+<html style="zoom: 1">
+  <div style="width: 250px; height: 250px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-003.html b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-003.html
new file mode 100644
index 0000000000000..b4bf803a896b6
--- /dev/null
+++ b/testing/web-platform/mozilla/tests/infrastructure/reftest-zoom/set-full-zoom-003.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+  <link rel="match" href="set-full-zoom-003-ref.html"/>
+  <meta name="assert" content="Initial zoom is equal to one."/>
+  <!-- Note that when running all the tests by alphabetical order, this test
+       would fail if set-zoom-002.html does not reset the zoom to one.
+       It would pass when re-running after a browser restart, though. -->
+  <div style="width: 250px; height: 250px; background: green"></div>
+</html>
diff --git a/testing/web-platform/mozilla/tests/mathml/README.md b/testing/web-platform/mozilla/tests/mathml/README.md
index 9ef8f4bf407b1..d579f67987272 100644
--- a/testing/web-platform/mozilla/tests/mathml/README.md
+++ b/testing/web-platform/mozilla/tests/mathml/README.md
@@ -66,3 +66,5 @@ any specification:
    [whitespace trimming in token elements](https://www.w3.org/TR/MathML3/chapter2.html#fund.collapse)
    which is not described in the initial version of MathML Core.
    See [issue 149](https://github.com/w3c/mathml-core/issues/149).
+
+- `zoom`: Tests to check MathML rendering at different zoom levels.
diff --git a/layout/reftests/mathml/radicalbar-1.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1.html
similarity index 88%
rename from layout/reftests/mathml/radicalbar-1.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1.html
index 326164c0fa555..1882b78275316 100644
--- a/layout/reftests/mathml/radicalbar-1.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1.html
@@ -1,13 +1,15 @@
 <!DOCTYPE html>
-  <html>
+<html>
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-1a.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1a.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-1a.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1a.html
index bf2e5147ae5fb..9d48a0971f9f5 100644
--- a/layout/reftests/mathml/radicalbar-1a.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1a.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom=".5">
+<html reftest-zoom=".5">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-1b.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1b.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-1b.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1b.html
index a469943e79067..d72cb252c792a 100644
--- a/layout/reftests/mathml/radicalbar-1b.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1b.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom=".4">
+<html reftest-zoom=".4">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-1c.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1c.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-1c.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1c.html
index 0485fe4136f24..d0708973f0ce1 100644
--- a/layout/reftests/mathml/radicalbar-1c.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1c.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom=".3">
+<html reftest-zoom=".3">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-1d.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1d.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-1d.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1d.html
index f89db4ded3ac2..91004d1acd464 100644
--- a/layout/reftests/mathml/radicalbar-1d.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-1d.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom=".2">
+<html reftest-zoom=".2">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-2.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2.html
similarity index 88%
rename from layout/reftests/mathml/radicalbar-2.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2.html
index 1870493cb4d64..2b5df8e97bfb0 100644
--- a/layout/reftests/mathml/radicalbar-2.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2.html
@@ -1,13 +1,15 @@
 <!DOCTYPE html>
-  <html>
+<html>
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-2a.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2a.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-2a.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2a.html
index 9856fa868cd6c..33368521ad410 100644
--- a/layout/reftests/mathml/radicalbar-2a.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2a.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.5">
+<html reftest-zoom="0.5">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-2b.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2b.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-2b.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2b.html
index 7df074c40eab8..b88f094c79877 100644
--- a/layout/reftests/mathml/radicalbar-2b.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2b.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.4">
+<html reftest-zoom="0.4">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-2c.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2c.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-2c.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2c.html
index 138bad31ab0c7..b9c83c19a3f32 100644
--- a/layout/reftests/mathml/radicalbar-2c.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2c.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.3">
+<html reftest-zoom="0.3">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-2d.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2d.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-2d.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2d.html
index 7f128824224cc..836f12b4e98b1 100644
--- a/layout/reftests/mathml/radicalbar-2d.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-2d.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.2">
+<html reftest-zoom="0.2">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-3.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3.html
similarity index 88%
rename from layout/reftests/mathml/radicalbar-3.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3.html
index 12fa3ae050383..245a1d6b6b04a 100644
--- a/layout/reftests/mathml/radicalbar-3.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3.html
@@ -1,13 +1,15 @@
 <!DOCTYPE html>
-  <html>
+<html>
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-3a.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3a.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-3a.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3a.html
index 24ebfec8e5ee9..30017437e5a47 100644
--- a/layout/reftests/mathml/radicalbar-3a.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3a.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.5">
+<html reftest-zoom="0.5">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-3b.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3b.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-3b.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3b.html
index 1aeafb6cb71ab..2f6ac92624bee 100644
--- a/layout/reftests/mathml/radicalbar-3b.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3b.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.4">
+<html reftest-zoom="0.4">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-3c.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3c.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-3c.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3c.html
index e9e7e7ae55329..5886cfeb63f14 100644
--- a/layout/reftests/mathml/radicalbar-3c.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3c.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.3">
+<html reftest-zoom="0.3">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
diff --git a/layout/reftests/mathml/radicalbar-3d.html b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3d.html
similarity index 84%
rename from layout/reftests/mathml/radicalbar-3d.html
rename to testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3d.html
index 7d780af44cd52..2802cb343e990 100644
--- a/layout/reftests/mathml/radicalbar-3d.html
+++ b/testing/web-platform/mozilla/tests/mathml/zoom/radicalbar-3d.html
@@ -1,13 +1,16 @@
 <!DOCTYPE html>
-  <html reftest-zoom="0.2">
+<html reftest-zoom="0.2">
   <head>
+    <link rel="mismatch" href="about:blank"/>
+    <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011020"/>
+    <script src="/_mozilla/common/reftest-zoom.js"></script>
     <!-- Default to invisible text -->
     <style type="text/css" media="screen, print">
       .hidden {
-        color: white;
+          color: white;
       }
       .visible {
-        color: black;
+          color: black;
       }
     </style>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>