diff --git a/resource-timing/nested-context-navigations-embed.html b/resource-timing/nested-context-navigations-embed.html
index bbba46c50edf21..5c8a62a9ae281d 100644
--- a/resource-timing/nested-context-navigations-embed.html
+++ b/resource-timing/nested-context-navigations-embed.html
@@ -9,11 +9,19 @@
 <script src="/common/get-host-info.sub.js"></script>
 <script src="resources/nested-contexts.js"></script>
 <script>
-    open_test_window("resources/embed-navigate-back.html",  "Test that embed navigations are not observable by the parent, even after history navigations by the parent");
-    open_test_window("resources/embed-navigate-back.html?crossorigin",  "Test that crossorigin embed navigations are not observable by the parent, even after history navigations by the parent");
-    open_test_window("resources/embed-navigate.html",  "Test that embed navigations are not observable by the parent");
-    open_test_window("resources/embed-navigate.html?crossorigin",  "Test that crossorigin embed navigations are not observable by the parent");
-    open_test_window("resources/embed-refresh.html",  "Test that embed refreshes are not observable by the parent");
-    open_test_window("resources/embed-refresh.html?crossorigin",  "Test that crossorigin embed refreshes are not observable by the parent");
+  open_test_window("resources/embed-navigate-back.html",
+    "Test that embed navigations are not observable by the parent, even " +
+    "after history navigations by the parent");
+  open_test_window("resources/embed-navigate-back.html?crossorigin",
+    "Test that crossorigin embed navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+  open_test_window("resources/embed-navigate.html",
+    "Test that embed navigations are not observable by the parent");
+  open_test_window("resources/embed-navigate.html?crossorigin",
+    "Test that crossorigin embed navigations are not observable by the parent");
+  open_test_window("resources/embed-refresh.html",
+    "Test that embed refreshes are not observable by the parent");
+  open_test_window("resources/embed-refresh.html?crossorigin",
+    "Test that crossorigin embed refreshes are not observable by the parent");
 </script>
 
diff --git a/resource-timing/nested-context-navigations-iframe.html b/resource-timing/nested-context-navigations-iframe.html
index 86a83285288a79..6e5cdd85c30d3e 100644
--- a/resource-timing/nested-context-navigations-iframe.html
+++ b/resource-timing/nested-context-navigations-iframe.html
@@ -9,11 +9,20 @@
 <script src="/common/get-host-info.sub.js"></script>
 <script src="resources/nested-contexts.js"></script>
 <script>
-    open_test_window("resources/iframe-navigate-back.html",  "Test that iframe navigations are not observable by the parent, even after history navigations by the parent");
-    open_test_window("resources/iframe-navigate-back.html?crossorigin",  "Test that crossorigin iframe navigations are not observable by the parent, even after history navigations by the parent");
-    open_test_window("resources/iframe-navigate.html",  "Test that iframe navigations are not observable by the parent");
-    open_test_window("resources/iframe-navigate.html?crossorigin",  "Test that crossorigin iframe navigations are not observable by the parent");
-    open_test_window("resources/iframe-refresh.html",  "Test that iframe refreshes are not observable by the parent");
-    open_test_window("resources/iframe-refresh.html?crossorigin",  "Test that crossorigin iframe refreshes are not observable by the parent");
+  open_test_window("resources/iframe-navigate-back.html",
+    "Test that iframe navigations are not observable by the parent, even " +
+    "after history navigations by the parent");
+  open_test_window("resources/iframe-navigate-back.html?crossorigin",
+    "Test that crossorigin iframe navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+  open_test_window("resources/iframe-navigate.html",
+    "Test that iframe navigations are not observable by the parent");
+  open_test_window("resources/iframe-navigate.html?crossorigin",
+    "Test that crossorigin iframe navigations are not observable by the " +
+    "parent");
+  open_test_window("resources/iframe-refresh.html",
+    "Test that iframe refreshes are not observable by the parent");
+  open_test_window("resources/iframe-refresh.html?crossorigin",
+    "Test that crossorigin iframe refreshes are not observable by the parent");
 </script>
 
diff --git a/resource-timing/nested-context-navigations-object.html b/resource-timing/nested-context-navigations-object.html
index 20cceea38d6ff2..8d63c5e3d44e5d 100644
--- a/resource-timing/nested-context-navigations-object.html
+++ b/resource-timing/nested-context-navigations-object.html
@@ -9,11 +9,20 @@
 <script src="/common/get-host-info.sub.js"></script>
 <script src="resources/nested-contexts.js"></script>
 <script>
-    open_test_window("resources/object-navigate-back.html",  "Test that object navigations are not observable by the parent, even after history navigations by the parent");
-    open_test_window("resources/object-navigate-back.html?crossorigin",  "Test that crossorigin object navigations are not observable by the parent, even after history navigations by the parent");
-    open_test_window("resources/object-navigate.html",  "Test that object navigations are not observable by the parent");
-    open_test_window("resources/object-navigate.html?crossorigin",  "Test that crossorigin object navigations are not observable by the parent");
-    open_test_window("resources/object-refresh.html",  "Test that object refreshes are not observable by the parent");
-    open_test_window("resources/object-refresh.html?crossorigin",  "Test that crossorigin object refreshes are not observable by the parent");
+  open_test_window("resources/object-navigate-back.html",
+    "Test that object navigations are not observable by the parent, even " +
+    "after history navigations by the parent");
+  open_test_window("resources/object-navigate-back.html?crossorigin",
+    "Test that crossorigin object navigations are not observable by the " +
+    "parent, even after history navigations by the parent");
+  open_test_window("resources/object-navigate.html",
+    "Test that object navigations are not observable by the parent");
+  open_test_window("resources/object-navigate.html?crossorigin",
+    "Test that crossorigin object navigations are not observable by the " +
+    "parent");
+  open_test_window("resources/object-refresh.html",
+    "Test that object refreshes are not observable by the parent");
+  open_test_window("resources/object-refresh.html?crossorigin",
+    "Test that crossorigin object refreshes are not observable by the parent");
 </script>
 
diff --git a/resource-timing/resources/document-navigated.html b/resource-timing/resources/document-navigated.html
index fa87355c3ed18f..bedae770824a3c 100644
--- a/resource-timing/resources/document-navigated.html
+++ b/resource-timing/resources/document-navigated.html
@@ -4,9 +4,9 @@
 <meta charset="utf-8" />
 </head>
 <body>
-    navigated document!
+  Navigated document!
 <script>
-    top.postMessage("navigated", "*");
+  top.postMessage("navigated", "*");
 </script>
 </body>
 </html>
diff --git a/resource-timing/resources/document-refreshed.html b/resource-timing/resources/document-refreshed.html
index 7e4ca09891ed35..568f7f27c7d950 100644
--- a/resource-timing/resources/document-refreshed.html
+++ b/resource-timing/resources/document-refreshed.html
@@ -4,9 +4,9 @@
 <meta charset="utf-8" />
 </head>
 <body>
-    Refreshed document!
+  Refreshed document!
 <script>
-    top.postMessage("refreshed", "*");
+  top.postMessage("refreshed", "*");
 </script>
 </body>
 </html>
diff --git a/resource-timing/resources/document-that-navigates.html b/resource-timing/resources/document-that-navigates.html
index cb567bf3d2ad12..a59e9f3ab2b783 100644
--- a/resource-timing/resources/document-that-navigates.html
+++ b/resource-timing/resources/document-that-navigates.html
@@ -5,7 +5,7 @@
 </head>
 <body>
 <script>
-    location.href="document-navigated.html";
+  location.href="document-navigated.html";
 </script>
 </body>
 </html>
diff --git a/resource-timing/resources/document-that-refreshes.html b/resource-timing/resources/document-that-refreshes.html
index 75522782a62dbe..659513a642f382 100644
--- a/resource-timing/resources/document-that-refreshes.html
+++ b/resource-timing/resources/document-that-refreshes.html
@@ -4,5 +4,6 @@
 <meta charset="utf-8" />
 <meta http-equiv="refresh" content="0;document-refreshed.html">
 </head>
-<body></body>
+<body>
+</body>
 </html>
diff --git a/resource-timing/resources/embed-navigate-back.html b/resource-timing/resources/embed-navigate-back.html
index ed14328190cddc..c9c7340f5307da 100644
--- a/resource-timing/resources/embed-navigate-back.html
+++ b/resource-timing/resources/embed-navigate-back.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing embed navigate - back button navigation</title>
-<body onunload="/*disable bfcache*/"></body>
+</head>
+<body onunload="/*disable bfcache*/">
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-setup_back_navigation("embed-navigate-back.html");
+  setup_back_navigation("embed-navigate-back.html");
 </script>
-<embed type="text/html">
+<embed id="target" type="text/html">
 <script>
-    document.getElementsByTagName("embed")[0].src = pre_navigate_url;
+  target.src = pre_navigate_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/embed-navigate.html b/resource-timing/resources/embed-navigate.html
index 20a73c662b4f7b..24c9d3c462730f 100644
--- a/resource-timing/resources/embed-navigate.html
+++ b/resource-timing/resources/embed-navigate.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing embed navigate</title>
+</head>
+<body>
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-    setup_navigate_test();
+  setup_navigate_test();
 </script>
-<div id=log></div>
-<embed type="text/html">
+<embed id="target" type="text/html">
 <script>
-    document.getElementsByTagName("embed")[0].src = pre_navigate_url;
+  target.src = pre_navigate_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/embed-refresh.html b/resource-timing/resources/embed-refresh.html
index 4a49fd0b4c1b54..bd4b5a14de9779 100644
--- a/resource-timing/resources/embed-refresh.html
+++ b/resource-timing/resources/embed-refresh.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing embed refresh</title>
+</head>
+<body>
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-    setup_refresh_test();
+  setup_refresh_test();
 </script>
-<div id=log></div>
-<embed type="text/html">
+<embed id="target" type="text/html">
 <script>
-    document.getElementsByTagName("embed")[0].src = pre_refresh_url;
+  target.src = pre_refresh_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/iframe-navigate-back.html b/resource-timing/resources/iframe-navigate-back.html
index ed2424cba3ab10..f944b633e2f207 100644
--- a/resource-timing/resources/iframe-navigate-back.html
+++ b/resource-timing/resources/iframe-navigate-back.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing iframe navigate - back button navigation</title>
-<body onunload="/*disable bfcache*/"></body>
+</head>
+<body onunload="/*disable bfcache*/">
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-setup_back_navigation("iframe-navigate-back.html");
+  setup_back_navigation("iframe-navigate-back.html");
 </script>
-<iframe></iframe>
+<iframe id="target"></iframe>
 <script>
-    document.getElementsByTagName("iframe")[0].src = pre_navigate_url;
+  target.src = pre_navigate_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/iframe-navigate.html b/resource-timing/resources/iframe-navigate.html
index 2a1a7e063619fe..02868840218953 100644
--- a/resource-timing/resources/iframe-navigate.html
+++ b/resource-timing/resources/iframe-navigate.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing iframe navigate</title>
+</head>
+<body>
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-    setup_navigate_test();
+  setup_navigate_test();
 </script>
-<div id=log></div>
-<iframe></iframe>
+<iframe id="target"></iframe>
 <script>
-    document.getElementsByTagName("iframe")[0].src = pre_navigate_url;
+  target.src = pre_navigate_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/iframe-refresh.html b/resource-timing/resources/iframe-refresh.html
index 4ce3ea0424297a..862b96da9dae68 100644
--- a/resource-timing/resources/iframe-refresh.html
+++ b/resource-timing/resources/iframe-refresh.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing iframe refresh</title>
+</head>
+<body>
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-    setup_refresh_test();
+  setup_refresh_test();
 </script>
-<div id=log></div>
-<iframe></iframe>
+<iframe id="target"></iframe>
 <script>
-    document.getElementsByTagName("iframe")[0].src = pre_refresh_url;
+  target.src = pre_refresh_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/nested-contexts.js b/resource-timing/resources/nested-contexts.js
index 07ef33851b0125..31bc97bb119399 100644
--- a/resource-timing/resources/nested-contexts.js
+++ b/resource-timing/resources/nested-contexts.js
@@ -1,97 +1,107 @@
 let destination = location;
 if (location.search == "?crossorigin") {
-    const host_info = get_host_info()
-    destination = location.protocol + "//" + host_info["REMOTE_HOST"] + ":" + location.port;
+  const {REMOTE_HOST} = get_host_info();
+  destination = `${location.protocol}//${REMOTE_HOST}:${location.port}`;
 }
 
-const pre_navigate_url = new URL("/resource-timing/resources/document-that-navigates.html", destination).href;
-const post_navigate_url = new URL("/resource-timing/resources/document-navigated.html", destination).href;
-const pre_refresh_url = new URL("/resource-timing/resources/document-that-refreshes.html", destination).href;
-const post_refresh_url = new URL("/resource-timing/resources/document-refreshed.html", destination).href;
+const pre_navigate_url =
+  new URL("/resource-timing/resources/document-that-navigates.html",
+    destination).href;
+const post_navigate_url =
+  new URL("/resource-timing/resources/document-navigated.html",
+    destination).href;
+const pre_refresh_url =
+  new URL("/resource-timing/resources/document-that-refreshes.html",
+    destination).href;
+const post_refresh_url =
+  new URL("/resource-timing/resources/document-refreshed.html",
+    destination).href;
 
-function setup_navigate_or_refresh(type, pre, post) {
-    function verify_document_navigate_not_observable() {
-        let entries = performance.getEntriesByType("resource");
-        let found_first_document = false;
-        for (entry of entries) {
-            if (entry.name == pre) {
-                found_first_document = true;
-            }
-            if (entry.name == post) {
-                opener.postMessage("FAIL - " + type + " document should not be observable", "*");
-                return;
-            }
-        }
-        if (!found_first_document) {
-            opener.postMessage("FAIL - initial document should be observable", "*");
-            return;
-        }
-        opener.postMessage("PASS", "*");
+const setup_navigate_or_refresh = (type, pre, post) => {
+  const verify_document_navigate_not_observable = () => {
+    const entries = performance.getEntriesByType("resource");
+    let found_first_document = false;
+    for (entry of entries) {
+      if (entry.name == pre) {
+        found_first_document = true;
+      }
+      if (entry.name == post) {
+        opener.postMessage(`FAIL - ${type} document should not be observable`,
+          `*`);
+        return;
+      }
     }
-    window.addEventListener("message", e=>{
-        if (e.data == type) {
-            verify_document_navigate_not_observable();
-        }
-    });
+    if (!found_first_document) {
+      opener.postMessage("FAIL - initial document should be observable", "*");
+      return;
+    }
+    opener.postMessage("PASS", "*");
+  }
+  window.addEventListener("message", e => {
+    if (e.data == type) {
+      verify_document_navigate_not_observable();
+    }
+  });
 }
 
-function setup_navigate_test() {
-    setup_navigate_or_refresh("navigated", pre_navigate_url, post_navigate_url);
+const setup_navigate_test = () => {
+  setup_navigate_or_refresh("navigated", pre_navigate_url, post_navigate_url);
 }
 
-function setup_refresh_test() {
-    setup_navigate_or_refresh("refreshed", pre_refresh_url, post_refresh_url);
+const setup_refresh_test = () => {
+  setup_navigate_or_refresh("refreshed", pre_refresh_url, post_refresh_url);
 }
 
-function setup_back_navigation(pushed_url) {
-    function verify_document_navigate_not_observable(navigated_back) {
-        let entries = performance.getEntriesByType("resource");
-        let found_first_document = false;
-        for (entry of entries) {
-            if (entry.name == pre_navigate_url) {
-                found_first_document = true;
-            }
-            if (entry.name == post_navigate_url) {
-                opener.postMessage("FAIL - navigated document exposed", "*");
-                return;
-            }
-        }
-        if (!found_first_document) {
-            opener.postMessage("FAIL - first document not exposed. navigated_back is " + navigated_back, "*");
-            return;
-        }
-        if (navigated_back) {
-            opener.postMessage("PASS", "*");
-        }
+const setup_back_navigation = pushed_url => {
+  const verify_document_navigate_not_observable = navigated_back => {
+    const entries = performance.getEntriesByType("resource");
+    let found_first_document = false;
+    for (entry of entries) {
+      if (entry.name == pre_navigate_url) {
+        found_first_document = true;
+      }
+      if (entry.name == post_navigate_url) {
+        opener.postMessage("FAIL - navigated document exposed", "*");
+        return;
+      }
     }
-    window.addEventListener("message", e=>{
-        if (e.data == "navigated") {
-            verify_document_navigate_not_observable(sessionStorage.navigated);
-            if (sessionStorage.navigated) {
-                delete sessionStorage.navigated;
-            } else {
-                sessionStorage.navigated = true;
-                setTimeout(() => {
-                    history.pushState({}, "", pushed_url);
-                    location.href="navigate_back.html";
-                }, 0);
-            }
-        }
-    });
+    if (!found_first_document) {
+      opener.postMessage(`FAIL - first document not exposed. navigated_back ` +
+        `is ${navigated_back}`, "*");
+      return;
+    }
+    if (navigated_back) {
+      opener.postMessage("PASS", "*");
+    }
+  }
+  window.addEventListener("message", e => {
+    if (e.data == "navigated") {
+      verify_document_navigate_not_observable(sessionStorage.navigated);
+      if (sessionStorage.navigated) {
+        delete sessionStorage.navigated;
+      } else {
+        sessionStorage.navigated = true;
+        setTimeout(() => {
+          history.pushState({}, "", pushed_url);
+          location.href="navigate_back.html";
+        }, 0);
+      }
+    }
+  });
 }
 
-function open_test_window(url, message) {
-    promise_test(() => {
-        return new Promise((resolve, reject) => {
-            let openee = window.open(url);
-            addEventListener("message", e => {
-                openee.close();
-                if (e.data == "PASS") {
-                    resolve();
-                } else {
-                    reject(e.data);
-                }
-            });
-        });
-    }, message);
+const open_test_window = (url, message) => {
+  promise_test(() => {
+    return new Promise((resolve, reject) => {
+      const openee = window.open(url);
+      addEventListener("message", e => {
+        openee.close();
+        if (e.data == "PASS") {
+          resolve();
+        } else {
+          reject(e.data);
+        }
+      });
+    });
+  }, message);
 }
diff --git a/resource-timing/resources/object-navigate-back.html b/resource-timing/resources/object-navigate-back.html
index 1023f984d5b9db..a746947818ffb4 100644
--- a/resource-timing/resources/object-navigate-back.html
+++ b/resource-timing/resources/object-navigate-back.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing object navigate - back button navigation</title>
-<body onunload="/*disable bfcache*/"></body>
+</head>
+<body onunload="/*disable bfcache*/">
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-setup_back_navigation("object-navigate-back.html");
+  setup_back_navigation("object-navigate-back.html");
 </script>
-<object type="text/html"></object>
+<object id="target" type="text/html"></object>
 <script>
-    document.getElementsByTagName("object")[0].data = pre_navigate_url;
+  target.data = pre_navigate_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/object-navigate.html b/resource-timing/resources/object-navigate.html
index 3ae39c8bc44fa7..6b4bb3128ee6f1 100644
--- a/resource-timing/resources/object-navigate.html
+++ b/resource-timing/resources/object-navigate.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing object navigate</title>
+</head>
+<body>
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-    setup_navigate_test();
+  setup_navigate_test();
 </script>
-<div id=log></div>
-<object type="text/html"></object>
+<object id="target" type="text/html"></object>
 <script>
-    document.getElementsByTagName("object")[0].data = pre_navigate_url;
+  target.data = pre_navigate_url;
 </script>
+</body>
+</html>
diff --git a/resource-timing/resources/object-refresh.html b/resource-timing/resources/object-refresh.html
index 9e43e19de19fc7..5c5f60fb06851a 100644
--- a/resource-timing/resources/object-refresh.html
+++ b/resource-timing/resources/object-refresh.html
@@ -3,13 +3,16 @@
 <head>
 <meta charset="utf-8" />
 <title>Resource Timing object refresh</title>
+</head>
+<body>
 <script src="/common/get-host-info.sub.js"></script>
 <script src="nested-contexts.js"></script>
 <script>
-    setup_refresh_test();
+  setup_refresh_test();
 </script>
-<div id=log></div>
-<object type="text/html"></object>
+<object id="target" type="text/html"></object>
 <script>
-    document.getElementsByTagName("object")[0].data = pre_refresh_url;
+  target.data = pre_refresh_url;
 </script>
+</body>
+</html>