diff --git a/html/partitioning/ancestor-chain-partitioning.sub.https.html b/html/partitioning/ancestor-chain-partitioning.sub.https.html
new file mode 100644
index 00000000000000..aee05dcddd1511
--- /dev/null
+++ b/html/partitioning/ancestor-chain-partitioning.sub.https.html
@@ -0,0 +1,66 @@
+<!doctype html>
+<meta charset=utf-8>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+<body>
+  <script>
+    async function getResultPromise(key) {
+      return new Promise((resolve) => {
+        window.addEventListener("message", (event) => {
+          if (event.data?.type != "result" || event.data?.key != key) {
+            return;
+          }
+          resolve(event.data.value);
+        });
+      });
+    }
+    localStorage.setItem("aba", "unpartitioned");
+    localStorage.setItem("aaa", "unpartitioned");
+    localStorage.setItem("aa-sw-redir", "unpartitioned");
+    let resultDataABA = getResultPromise("aba");
+    let resultDataAAA = getResultPromise("aaa");
+    let resultDataAASW = getResultPromise("aa-sw-redir");
+    let resultDataPopup = getResultPromise("popup");
+  </script>
+  <iframe src="//{{hosts[alt][www]}}:{{ports[https][0]}}{{location[path]}}/../resources/middle-frame.sub.html?key=aba"></iframe>
+  <iframe src="//{{hosts[][]}}:{{ports[https][0]}}{{location[path]}}/../resources/middle-frame.sub.html?key=aaa"></iframe>
+  <iframe id="aa-sw-redir"></iframe>
+  <script>
+    promise_test(async function() {
+      document.cookie = "unpartitioned=true; Secure; SameSite=None";
+      let win = window.open("//{{hosts[][]}}:{{ports[https][0]}}{{location[path]}}/../resources/popup.sub.html?key=popup&cookie");
+      let value = await resultDataPopup;
+      assert_equals(value, "", "Expected partitioned data in sandboxA(B) iframe");
+      win?.close();
+      this.add_cleanup(test_driver.delete_all_cookies);
+    }, "Expected partitioned data in sandboxA(B) iframe")
+
+    promise_test(async function() {
+      let value = await resultDataABA;
+      assert_equals(value, null, "Expected partitioned data in A(B(A)) nested frame");
+      localStorage.removeItem("aba");
+    }, "Expected partitioned data in A(B(A)) nested frame")
+
+    promise_test(async function() {
+      let value = await resultDataAAA;
+      assert_equals(value, "unpartitioned", "Expected unpartitioned data in A(A(A)) nested frame");
+      localStorage.removeItem("aaa");
+    }, "Expected unpartitioned data in A(A(A)) nested frame")
+
+    promise_test(async function() {
+      let registration = await navigator.serviceWorker.register("./resources/intercepting-worker.sub.js");
+      this.add_cleanup(async function() {
+        await registration.unregister();
+      });
+
+      let innerFrame = document.getElementById("aa-sw-redir");
+      innerFrame.src ="//{{hosts[][]}}:{{ports[https][0]}}{{location[path]}}/../resources/post-storage.sub.html?key=aa-sw-redir&intercept";
+
+      let value = await resultDataAASW;
+      assert_equals(value, "unpartitioned", "Expected unpartitioned data in same-origin subframe redirected by service worker");
+
+      localStorage.removeItem("aa-sw-redir");
+    }, "Expected unpartitioned data in same-origin subframe redirected by service worker")
+  </script>
diff --git a/html/partitioning/resources/intercepting-worker.sub.js b/html/partitioning/resources/intercepting-worker.sub.js
new file mode 100644
index 00000000000000..65c096da78ff62
--- /dev/null
+++ b/html/partitioning/resources/intercepting-worker.sub.js
@@ -0,0 +1,11 @@
+self.addEventListener("fetch", (event) => {
+  let url = new URL(event.request.url);
+  if (url.searchParams.has("intercept")) {
+    if (url.hostname == "{{hosts[][]}}") {
+      url.hostname = "{{hosts[alt][www]}}"
+    } else {
+      url.hostname = "{{hosts[][]}}";
+    }
+    return event.respondWith(fetch(url));
+  }
+});
diff --git a/html/partitioning/resources/middle-frame.sub.html b/html/partitioning/resources/middle-frame.sub.html
new file mode 100644
index 00000000000000..811271b3b86a1c
--- /dev/null
+++ b/html/partitioning/resources/middle-frame.sub.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<meta charset=utf-8>
+<body>
+  <iframe id="innerFrame"></iframe>
+  <script>
+    window.addEventListener("message", (event) => {
+      if (event.data?.type != "result") {
+        return;
+      }
+      parent.postMessage(event.data, "*");
+    });
+    let innerFrame = document.getElementById("innerFrame");
+    innerFrame.src ="//{{hosts[][]}}:{{ports[https][0]}}{{location[path]}}/../../resources/post-storage.sub.html{{location[query]}}";
+  </script>
diff --git a/html/partitioning/resources/popup.sub.html b/html/partitioning/resources/popup.sub.html
new file mode 100644
index 00000000000000..b6ae4359a210b0
--- /dev/null
+++ b/html/partitioning/resources/popup.sub.html
@@ -0,0 +1,15 @@
+<!doctype html>
+<meta charset=utf-8>
+<body>
+  <iframe id="innerFrame"></iframe>
+  <script>
+    window.addEventListener("message", (event) => {
+      if (event.data?.type != "result") {
+        return;
+      }
+      window.opener.postMessage(event.data, "*");
+    });
+    let innerFrame = document.getElementById("innerFrame");
+    let queryParams = "{{location[query]}}".replace("&amp;", "&"); // un-escape the templated string.
+    innerFrame.src ="//{{hosts[alt][www]}}:{{ports[https][0]}}{{location[path]}}/../../resources/post-storage.sub.html" + queryParams;
+  </script>
diff --git a/html/partitioning/resources/popup.sub.html.headers b/html/partitioning/resources/popup.sub.html.headers
new file mode 100644
index 00000000000000..e2d945d55669ec
--- /dev/null
+++ b/html/partitioning/resources/popup.sub.html.headers
@@ -0,0 +1 @@
+Content-Security-Policy: sandbox allow-scripts;
\ No newline at end of file
diff --git a/html/partitioning/resources/post-storage.html b/html/partitioning/resources/post-storage.html
new file mode 100644
index 00000000000000..3ca1926eaa80c4
--- /dev/null
+++ b/html/partitioning/resources/post-storage.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<meta charset=utf-8>
+<body>
+  <script>
+    const urlParams = new URLSearchParams(window.location.search);
+    let key = urlParams.get("key");
+    let result = localStorage.getItem(key);
+    if (urlParams.has("store")) {
+      localStorage.setItem(key, urlParams.get("store"));
+    }
+    parent.postMessage({
+      type: "result",
+      value: result,
+      key,
+    }, "*");
+  </script>
diff --git a/html/partitioning/resources/post-storage.html.sub.headers b/html/partitioning/resources/post-storage.html.sub.headers
new file mode 100644
index 00000000000000..1f73a789e4e2a5
--- /dev/null
+++ b/html/partitioning/resources/post-storage.html.sub.headers
@@ -0,0 +1 @@
+Access-Control-Allow-Origin: {{header_or_default(Origin, *)}}
\ No newline at end of file
diff --git a/html/partitioning/resources/post-storage.sub.html b/html/partitioning/resources/post-storage.sub.html
new file mode 100644
index 00000000000000..6e96d21c241c80
--- /dev/null
+++ b/html/partitioning/resources/post-storage.sub.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<meta charset=utf-8>
+<body>
+  <script>
+    const urlParams = new URLSearchParams(window.location.search);
+    let key = urlParams.get("key");
+    let result;
+    if (urlParams.has("cookie")) {
+      result = "{{header_or_default(cookie, )}}";
+    } else {
+      result = localStorage.getItem(key);
+      if (urlParams.has("store")) {
+        localStorage.setItem(key, urlParams.get("store"));
+      }
+    }
+    parent.postMessage({
+      type: "result",
+      value: result,
+      key,
+    }, "*");
+  </script>
diff --git a/html/partitioning/resources/post-storage.sub.html.headers b/html/partitioning/resources/post-storage.sub.html.headers
new file mode 100644
index 00000000000000..1f73a789e4e2a5
--- /dev/null
+++ b/html/partitioning/resources/post-storage.sub.html.headers
@@ -0,0 +1 @@
+Access-Control-Allow-Origin: {{header_or_default(Origin, *)}}
\ No newline at end of file
