--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -288308,21 +288308,16 @@
      {}
     ]
    ],
    "html/webappapis/dynamic-markup-insertion/document-writeln/original-id.json": [
     [
      {}
     ]
    ],
-   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/004-1.html": [
-    [
-     {}
-    ]
-   ],
    "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/010-1.html": [
     [
      {}
     ]
    ],
    "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/010-2.html": [
     [
      {}
@@ -363574,22 +363569,16 @@
     ]
    ],
    "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/006.html": [
     [
      "/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/006.html",
      {}
     ]
    ],
-   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/007.html": [
-    [
-     "/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/007.html",
-     {}
-    ]
-   ],
    "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/008.html": [
     [
      "/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/008.html",
      {}
     ]
    ],
    "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/009.https.html": [
     [
@@ -603673,42 +603662,34 @@
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/001.html": [
    "f82d80be7b6b50608699b73a6f8d1b592e0a55c6",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/002.html": [
    "5584bf9afbff034f5ea68d769afa648e31fe1aaf",
    "testharness"
   ],
-  "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/004-1.html": [
-   "c50eddd41faba2ecc8928e459288fe612b999170",
-   "support"
-  ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/004.html": [
-   "0b3220279fd56148a36d2085563056827702018d",
+   "3fb443a99314aa26e230fe63d7f58a78141b0a71",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/005.html": [
-   "24725b76fb1c3aeb2ab4935b3fc95589375e4a4a",
+   "e849c31560e8fc55afef26023d80b7ef0886ba85",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/006.html": [
-   "ae5edc457dacd5c1a06169fa0fda96396dfc0f21",
-   "testharness"
-  ],
-  "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/007.html": [
-   "e5f0d1561ef6e9cd33393914e087e33fca73fefe",
+   "1dcb92615d085b28d3c9d2a22d744be849158d18",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/008.html": [
-   "7471b2203169fd0cc74c9572a9c207dd4eb099a0",
+   "36c0a3f3ea11b9f96522cbba22f1006ba42900bb",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/009.https.html": [
-   "3f51fa40dfa50cfaa8f6eb3b05d725255960d139",
+   "0d104c9569b37355c24d60fdcad0ca9ed792dcd0",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/010-1.html": [
    "317e13691d4a94e5861bbb85d7367591d7d1c624",
    "support"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/010-2.html": [
    "ea537fcd6018fab07cb58132a2523d82cb8783de",
@@ -603806,17 +603787,17 @@
    "fc325d54db239d729a4b762367576494c9e93490",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/encoding.window.js": [
    "f0d133a5329017814f21b206934a554955d15f88",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/event-listeners.window.js": [
-   "97334ce1bab8f15f85361f50117106a7ac1aa782",
+   "58ec08f9ff110a458f02660ba18e97513f569173",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/ignore-opens-during-unload.window.js": [
    "5de4b1421b5ef10adecb10a2d5bda0d3a2c2711c",
    "testharness"
   ],
   "html/webappapis/dynamic-markup-insertion/opening-the-input-stream/mutation-events.window.js": [
    "4efbb863c6372a3ee04d11f38d7ee56a44a2ac7d",

deleted file mode 100644
--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/004-1.html
+++ /dev/null
@@ -1,1 +0,0 @@
-<!doctype html>

--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/004.html
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/004.html
@@ -1,14 +1,14 @@
 <!doctype html>
 <title>Reuse of document object after document.open</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
-<iframe src="004-1.html"></iframe>
+<iframe src="/common/blank.html"></iframe>
 <script>
 var t = async_test();
 var iframe;
 onload = t.step_func(function() {
   var iframe = document.getElementsByTagName("iframe")[0];
   var handle = iframe.contentDocument;
   iframe.contentDocument.test_state = 1;
   assert_equals(iframe.contentDocument.open(), handle);

--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/005.html
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/005.html
@@ -1,14 +1,14 @@
 <!doctype html>
 <title>Cancelling timeout after document.open</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
-<iframe src="004-1.html"></iframe>
+<iframe src="/common/blank.html"></iframe>
 <script>
 var t = async_test();
 var iframe;
 onload = t.step_func(function() {
   var iframe = document.getElementsByTagName("iframe")[0];
   iframe.contentWindow.setTimeout(t.step_func(function() {assert_unreached()}), 100);
   assert_equals(iframe.contentDocument.open(), iframe.contentDocument);
   setTimeout(function() {t.done();}, 200);

--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/006.html
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/006.html
@@ -1,14 +1,14 @@
 <!doctype html>
 <title>Cancelling error after document.open</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
-<iframe src="004-1.html"></iframe>
+<iframe src="/common/blank.html"></iframe>
 <script>
 var t = async_test();
 var iframe;
 onload = t.step_func(function() {
   var iframe = document.getElementsByTagName("iframe")[0];
   var img = iframe.contentDocument.createElement("img");
   img.onerror = t.step_func(function() {assert_unreached()})
   img.src = "missing";

deleted file mode 100644
--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/007.html
+++ /dev/null
@@ -1,19 +0,0 @@
-<!doctype html>
-<title>Unregistering event handlers after document.open</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<div id="log"></div>
-<iframe src="004-1.html"></iframe>
-<script>
-var t = async_test();
-var iframe;
-onload = t.step_func(function() {
-  var iframe = document.getElementsByTagName("iframe")[0];
-  iframe.contentDocument.onclick = t.step_func(function() {assert_unreached()})
-  iframe.contentDocument.open();
-  var e = iframe.contentDocument.createEvent("mouseevents")
-  e.initEvent("click", false, false);
-  iframe.contentDocument.dispatchEvent(e);
-  setTimeout(function() {t.done();}, 500);
-});
-</script>

--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/008.html
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/008.html
@@ -1,14 +1,14 @@
 <!doctype html>
 <title>Replacement of document prototype object after document.open</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
-<iframe src="004-1.html"></iframe>
+<iframe src="/common/blank.html"></iframe>
 <script>
 var t = async_test();
 var iframe;
 onload = t.step_func(function() {
   var iframe = document.getElementsByTagName("iframe")[0];
   var handle = Object.getPrototypeOf(iframe.contentDocument);
   handle.test_state = 1;
   assert_equals(iframe.contentDocument.open(), iframe.contentDocument);

--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/009.https.html
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/009.https.html
@@ -1,14 +1,14 @@
 <!doctype html>
 <title>document.open replacing singleton</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
-<iframe src="004-1.html"></iframe>
+<iframe src="/common/blank.html"></iframe>
 <script>
 var iframe = document.getElementsByTagName("iframe")[0];
 var steps;
 iframe.onload = function() {
 steps = ["window", "location", "history", "navigator", "applicationCache", "sessionStorage", "localStorage", "locationbar"].map(
 function(x) {
   var t = async_test(document.title + " " + x);
   var handle = iframe.contentWindow[x];

--- a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/event-listeners.window.js
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/event-listeners.window.js
@@ -1,19 +1,87 @@
+test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe")),
+        body = frame.contentDocument.body;
+  t.add_cleanup(() => frame.remove());
+  const div = body.appendChild(frame.contentDocument.createElement("div"));
+  div.addEventListener("click", t.unreached_func("element event listener not removed"));
+  frame.contentDocument.open();
+  div.click();
+  frame.contentDocument.close();
+}, "Standard event listeners are to be removed");
+
 test(t => {
   const frame = document.body.appendChild(document.createElement("iframe")),
         body = frame.contentDocument.body;
   t.add_cleanup(() => frame.remove());
   frame.contentDocument.addEventListener("x", t.unreached_func("document event listener not removed"));
   body.addEventListener("x", t.unreached_func("body event listener not removed"));
   frame.contentDocument.open();
   frame.contentDocument.dispatchEvent(new Event("x"));
   body.dispatchEvent(new Event("x"));
   frame.contentDocument.close();
-}, "Event listeners are to be removed");
+}, "Custom event listeners are to be removed");
+
+test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe")),
+        body = frame.contentDocument.body;
+  t.add_cleanup(() => frame.remove());
+  // Focus on the current window so that the frame's window is blurred.
+  window.focus();
+  assert_false(frame.contentDocument.hasFocus());
+  frame.contentWindow.addEventListener("focus", t.unreached_func("window event listener not removed"));
+  body.onfocus = t.unreached_func("body event listener not removed");
+  frame.contentDocument.open();
+  assert_equals(body.onfocus, null);
+  frame.contentWindow.focus();
+  frame.contentDocument.close();
+}, "Standard event listeners are to be removed from Window");
+
+test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe"));
+  t.add_cleanup(() => frame.remove());
+  frame.contentWindow.addEventListener("x", t.unreached_func("window event listener not removed"));
+  frame.contentDocument.open();
+  frame.contentWindow.dispatchEvent(new Event("x"));
+  frame.contentDocument.close();
+}, "Custom event listeners are to be removed from Window");
+
+test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe")),
+        body = frame.contentDocument.body;
+  t.add_cleanup(() => frame.remove());
+  const div = body.appendChild(frame.contentDocument.createElement("div"));
+  div.onclick = t.unreached_func("element event listener not removed");
+  frame.contentDocument.open();
+  assert_equals(div.onclick, null);
+  const e = frame.contentDocument.createEvent("mouseevents")
+  e.initEvent("click", false, false);
+  div.dispatchEvent(e);
+  frame.contentDocument.close();
+}, "IDL attribute event handlers are to be deactivated");
+
+var thrower;
+
+test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe")),
+        body = frame.contentDocument.body;
+  t.add_cleanup(() => frame.remove());
+  const div = body.appendChild(frame.contentDocument.createElement("div"));
+  thrower = t.step_func(() => { throw new Error('element event listener not removed'); });
+  div.setAttribute("onclick", "parent.thrower()");
+  assert_not_equals(div.onclick, null);
+  frame.contentDocument.open();
+  assert_equals(div.getAttribute("onclick"), "parent.thrower()");
+  assert_equals(div.onclick, null);
+  const e = frame.contentDocument.createEvent("mouseevents")
+  e.initEvent("click", false, false);
+  div.dispatchEvent(e);
+  frame.contentDocument.close();
+}, "Content attribute event handlers are to be deactivated");
 
 test(t => {
   const frame = document.body.appendChild(document.createElement("iframe"));
   t.add_cleanup(() => frame.remove());
   let once = false;
   frame.contentDocument.addEventListener("x", () => {
     frame.contentDocument.open();
     once = true;