--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -287466,16 +287466,21 @@
      {}
     ]
    ],
    "html/semantics/embedded-content/resources/should-not-load.html": [
     [
      {}
     ]
    ],
+   "html/semantics/embedded-content/resources/test_page.html": [
+    [
+     {}
+    ]
+   ],
    "html/semantics/embedded-content/svg/.gitkeep": [
     [
      {}
     ]
    ],
    "html/semantics/embedded-content/the-area-element/.gitkeep": [
     [
      {}
@@ -341091,16 +341096,22 @@
     ]
    ],
    "html/semantics/embedded-content/the-canvas-element/type.replace.html": [
     [
      "/html/semantics/embedded-content/the-canvas-element/type.replace.html",
      {}
     ]
    ],
+   "html/semantics/embedded-content/the-embed-element/detach-frame-on-src-change.html": [
+    [
+     "/html/semantics/embedded-content/the-embed-element/detach-frame-on-src-change.html",
+     {}
+    ]
+   ],
    "html/semantics/embedded-content/the-embed-element/document-getters-return-null-for-cross-origin.html": [
     [
      "/html/semantics/embedded-content/the-embed-element/document-getters-return-null-for-cross-origin.html",
      {}
     ]
    ],
    "html/semantics/embedded-content/the-embed-element/embed-dimension.html": [
     [
@@ -341665,16 +341676,22 @@
     ]
    ],
    "html/semantics/embedded-content/the-img-element/usemap-casing.html": [
     [
      "/html/semantics/embedded-content/the-img-element/usemap-casing.html",
      {}
     ]
    ],
+   "html/semantics/embedded-content/the-object-element/detach-frame-on-data-change.html": [
+    [
+     "/html/semantics/embedded-content/the-object-element/detach-frame-on-data-change.html",
+     {}
+    ]
+   ],
    "html/semantics/embedded-content/the-object-element/document-getters-return-null-for-cross-origin.html": [
     [
      "/html/semantics/embedded-content/the-object-element/document-getters-return-null-for-cross-origin.html",
      {}
     ]
    ],
    "html/semantics/embedded-content/the-object-element/historical.html": [
     [
@@ -578734,16 +578751,20 @@
   "html/semantics/embedded-content/resources/should-load.html": [
    "7cc95b9b2eb8c3f2d89278d22db271b9ae42e107",
    "support"
   ],
   "html/semantics/embedded-content/resources/should-not-load.html": [
    "a1657fc9e655ad0a30ced47a1412b6c34ba964b9",
    "support"
   ],
+  "html/semantics/embedded-content/resources/test_page.html": [
+   "7865ad89746586ea71fa92621192417de57223ca",
+   "support"
+  ],
   "html/semantics/embedded-content/svg/.gitkeep": [
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
   "html/semantics/embedded-content/the-area-element/.gitkeep": [
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
@@ -579458,16 +579479,20 @@
   "html/semantics/embedded-content/the-canvas-element/type.replace.html": [
    "c8784361857ba83afbe1be4bca4ed5e654307c2f",
    "testharness"
   ],
   "html/semantics/embedded-content/the-embed-element/.gitkeep": [
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
+  "html/semantics/embedded-content/the-embed-element/detach-frame-on-src-change.html": [
+   "55e68ad2312d4079ce4be558ef361f6f56977d58",
+   "testharness"
+  ],
   "html/semantics/embedded-content/the-embed-element/document-getters-return-null-for-cross-origin.html": [
    "3d75c8c998b3f98f2023311826dcd1d4c21d3361",
    "testharness"
   ],
   "html/semantics/embedded-content/the-embed-element/embed-dimension.html": [
    "6f8443aada05e8ab3cbb81d81d7053a81fe0dcfe",
    "testharness"
   ],
@@ -580194,16 +580219,20 @@
   "html/semantics/embedded-content/the-map-element/.gitkeep": [
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
   "html/semantics/embedded-content/the-object-element/.gitkeep": [
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
+  "html/semantics/embedded-content/the-object-element/detach-frame-on-data-change.html": [
+   "c534d05044768f72015e9cea7dd45b582ecf0368",
+   "testharness"
+  ],
   "html/semantics/embedded-content/the-object-element/document-getters-return-null-for-cross-origin.html": [
    "f9f22673579147c7591d5f71467d6655140702b9",
    "testharness"
   ],
   "html/semantics/embedded-content/the-object-element/historical.html": [
    "3efc9442872199305ef71c7c29331ae465fb8395",
    "testharness"
   ],

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/embedded-content/resources/test_page.html
@@ -0,0 +1,3 @@
+<!doctype html>
+<title> An empty test page </title>
+<p> This is test page </p>

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/embedded-content/the-embed-element/detach-frame-on-src-change.html
@@ -0,0 +1,82 @@
+<!doctype html>
+<html>
+<head>
+  <title>
+    &lt;embed&gt;'s browsing context is discarded on 'src' attribute change.
+  </title>
+  <link rel="author" title="Ehsan Karamad" href="ekaramad@chromium.org">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+  <script>
+    let url1 = "../resources/test_page.html";
+    let url2 = "../resources/should-load.html";
+    function onLoadPromise(el) {
+      return new Promise((resolve) => {
+        function onLoad() {
+          resolve();
+          el.removeEventListener("load", onLoad);
+        }
+        el.addEventListener("load", onLoad);
+      });
+    }
+
+    promise_test(async() => {
+      let old_windows = [];
+
+      let embed = document.createElement("embed");
+      embed.type = "text/html";
+      embed.src = url1;
+      let onEmbedLoad = onLoadPromise(embed);
+      document.body.appendChild(embed);
+      await onEmbedLoad;
+      old_windows.push(window[0]);
+      assert_equals(
+        window[0].frameElement,
+        embed,
+        "<embed> is attached and loaded with html content.");
+
+      let iframe = document.createElement("iframe");
+      iframe.src = url1;
+      let onIframeLoad = onLoadPromise(iframe);
+      document.body.appendChild(iframe);
+      await onIframeLoad;
+      old_windows.push(window[1]);
+      assert_equals(
+        window[1].frameElement,
+        iframe,
+        "<iframe> is attached and loaded with html content after <embed>.");
+      assert_equals(
+        window[0],
+        old_windows[0],
+        "The first window is that of <embed>'s frame.");
+
+      // Now navigate the embed element again.
+      onEmbedLoad = onLoadPromise(embed);
+      embed.src = url2;
+      await onEmbedLoad;
+      assert_equals(
+        window[0].frameElement,
+        iframe,
+        "<embed>'s previous frame must have been destroyed.");
+
+      assert_equals(
+        window[1].frameElement,
+        embed,
+        "<embed>'s new window should be appended after navigation.");
+
+      assert_not_equals(
+        old_windows[0],
+        window[1],
+        "The old window and new window are different for <embed>.");
+
+      assert_equals(
+        old_windows[1],
+        window[0],
+        "The old and new window are the same for <iframe>.");
+    }, "Verify that changing 'src' attribute of an <embed> element discards" +
+       " the old browsing context and creates a new browsing context.");
+  </script>
+</body>
+</html>

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/embedded-content/the-object-element/detach-frame-on-data-change.html
@@ -0,0 +1,83 @@
+<!doctype html>
+<html>
+<head>
+  <title>
+    &lt;object&gt;'s browsing context is discarded on 'data' attribute change.
+  </title>
+  <link rel="author" title="Ehsan Karamad" href="ekaramad@chromium.org">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+  <script>
+    let url1 = "../resources/test_page.html";
+    let url2 = "../resources/should-load.html";
+    function onLoadPromise(el) {
+      return new Promise((resolve) => {
+        function onLoad() {
+          resolve();
+          el.removeEventListener("load", onLoad);
+        }
+        el.addEventListener("load", onLoad);
+      });
+    }
+
+    promise_test(async() => {
+      let old_windows = [];
+
+      let object = document.createElement("object");
+      object.type = "text/html";
+      object.data = url1;
+      let onObjectLoad = onLoadPromise(object);
+      document.body.appendChild(object);
+      await onObjectLoad;
+      old_windows.push(window[0]);
+      assert_equals(
+        window[0].frameElement,
+        object,
+        "<object> is attached and loaded with html content.");
+
+      let iframe = document.createElement("iframe");
+      iframe.src = url1;
+      let onIframeLoad = onLoadPromise(iframe);
+      document.body.appendChild(iframe);
+      await onIframeLoad;
+      old_windows.push(window[1]);
+      assert_equals(
+        window[1].frameElement,
+        iframe,
+        "<iframe> is attached and loaded with html content after <object>.");
+      assert_equals(
+        window[0],
+        old_windows[0],
+        "The first window is that of <object>'s frame.");
+
+      // Now navigate the object element again.
+      onObjectLoad = onLoadPromise(object);
+      object.data = url2;
+      await onObjectLoad;
+      assert_equals(
+        window[0].frameElement,
+        iframe,
+        "<object>'s previous frame must have been destroyed.");
+
+      assert_equals(
+        window[1].frameElement,
+        object,
+        "<object>'s new window should be appended after navigation.");
+
+      assert_not_equals(
+        old_windows[0],
+        window[1],
+        "The old window and new window are different for <object>.");
+
+      assert_equals(
+        old_windows[1],
+        window[0],
+        "The old and new window are the same for <iframe>.");
+
+    }, "Verify that changing 'data' attribute of an <object> element discards" +
+       " the old browsing context and creates a new browsing context.");
+  </script>
+</body>
+</html>