diff --git a/html/semantics/popups/popup-css-properties.tentative.html b/html/semantics/popups/popup-css-properties.tentative.html
deleted file mode 100644
index ac5e9f7f2f4117..00000000000000
--- a/html/semantics/popups/popup-css-properties.tentative.html
+++ /dev/null
@@ -1,54 +0,0 @@
-<!DOCTYPE html>
-<meta charset="utf-8">
-<title>Pop-up API CSS parsing with computed values</title>
-<link rel="author" href="mailto:masonf@chromium.org">
-<link rel=help href="https://open-ui.org/components/popUp.research.explainer">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="/css/support/parsing-testcommon.js"></script>
-<script src="/css/support/computed-testcommon.js"></script>
-<script src="/css/support/interpolation-testcommon.js"></script>
-
-<div id=target></div>
-<div id=scratch></div>
-
-<script>
-function testprop(prop) {
-  // Computed values:
-  test_computed_value(prop, '0s');
-  test_computed_value(prop, '0ms', '0s');
-  test_computed_value(prop, '32s');
-  test_computed_value(prop, '123ms', '0.123s');
-
-  // Valid values:
-  test_valid_value(prop, '0s');
-  test_valid_value(prop, '0ms');
-  test_valid_value(prop, '32s');
-  test_valid_value(prop, '123ms');
-  test_valid_value(prop, 'inherit');
-
-  // Invalid values:
-  test_invalid_value(prop, '0');
-  test_invalid_value(prop, 'foo');
-  test_invalid_value(prop, '-1s');
-  test_invalid_value(prop, 'none');
-  test_invalid_value(prop, 'auto');
-
-  // Animations:
-  test_interpolation({
-    property: prop,
-    from: '1s',
-    to: '2000ms',
-  }, [
-    {at: -1.5, expect: '0s'}, // Clamping at 0
-    {at: -0.3, expect: '0.7s'},
-    {at: 0, expect: '1s'},
-    {at: 0.5, expect: '1.5s'},
-    {at: 1, expect: '2s'},
-    {at: 1.5, expect: '2.5s'},
-  ]);
-}
-
-testprop('pop-up-show-delay');
-testprop('pop-up-hide-delay');
-</script>
diff --git a/html/semantics/popups/popup-hover-hide.tentative.html b/html/semantics/popups/popup-hover-hide.tentative.html
deleted file mode 100644
index 16acd687aae657..00000000000000
--- a/html/semantics/popups/popup-hover-hide.tentative.html
+++ /dev/null
@@ -1,128 +0,0 @@
-<!DOCTYPE html>
-<meta charset="utf-8" />
-<title>The pop-up-hide-delay CSS property</title>
-<link rel="author" href="mailto:masonf@chromium.org">
-<link rel=help href="https://open-ui.org/components/popup.research.explainer">
-<meta name="timeout" content="long">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="/resources/testdriver.js"></script>
-<script src="/resources/testdriver-actions.js"></script>
-<script src="/resources/testdriver-vendor.js"></script>
-<script src="resources/popup-utils.js"></script>
-
-<style>
-  [popup] {
-    top:100px;
-    pop-up-hide-delay: 100ms;
-  }
-  [popuphovertarget] {
-    top:200px;
-    pop-up-show-delay: 100ms;
-  }
-  #unrelated {top: 300px;}
-  div {
-    /* Fixed position everything to ensure nothing overlaps */
-    position: fixed;
-  }
-</style>
-<div id=unrelated>Unrelated element</div>
-
-<div popup id=example1>Pop-up</div>
-<div popuphovertarget=example1 id=invoker1>Hover me</div>
-
-<script>
-const hoverDelays = 100; // This needs to match the style block above.
-const hoverWaitTime = 200; // How long to wait to cover the delay for sure.
-
-// NOTE about testing methodology:
-// This test checks whether pop-ups are hidden *after* the appropriate de-hover
-// delay. The delay used for testing is kept low, to avoid this test taking too
-// long, but that means that sometimes on a slow bot/client, the delay can
-// elapse before we are able to check the pop-up status. And that can make this
-// test flaky. To avoid that, the msSinceMouseOver() function is used to check
-// that not-too-much time has passed, and if it has, the test is simply skipped.
-
-const unrelated = document.getElementById('unrelated');
-
-function getComputedStyleTimeMs(element,property) {
-  // Times are in seconds, so just strip off the 's'.
-  return Number(getComputedStyle(element)[property].slice(0,-1))*1000;
-}
-
-promise_test(async (t) => {
-  await mouseOver(unrelated);
-  const popUp = document.getElementById('example1');
-  assert_false(popUp.matches(':top-layer'));
-  popUp.showPopUp();
-  assert_true(popUp.matches(':top-layer'));
-  await waitForHoverTime(hoverWaitTime);
-  assert_false(popUp.matches(':top-layer'));
-  assert_true(msSinceMouseOver() >= hoverWaitTime,'waitForHoverTime should wait the specified time');
-  assert_true(hoverWaitTime > hoverDelays,'hoverDelays is the value from CSS, hoverWaitTime should be longer than that');
-  assert_equals(getComputedStyleTimeMs(invoker1,'popUpShowDelay'),hoverDelays,'pop-up-show-delay is incorrect');
-  assert_equals(getComputedStyleTimeMs(popUp,'popUpHideDelay'),hoverDelays,'pop-up-hide-delay is incorrect');
-},`The pop-up-hide-delay causes a pop-up to be hidden after a delay`);
-
-promise_test(async (t) => {
-  await mouseOver(unrelated);
-  const popUp = document.getElementById('example1');
-  assert_false(popUp.matches(':top-layer'));
-  popUp.showPopUp();
-  await mouseOver(popUp);
-  await waitForHoverTime(hoverWaitTime);
-  assert_true(popUp.matches(':top-layer'),'hovering the pop-up should keep it showing');
-  await mouseOver(unrelated);
-  let showing = popUp.matches(':top-layer');
-  if (msSinceMouseOver() >= hoverDelays)
-    return; // The WPT runner was too slow.
-  assert_true(showing,'hovering unrelated element shouldn\'t immediately hide the pop-up');
-  await waitForHoverTime(hoverWaitTime);
-  assert_false(popUp.matches(':top-layer'),'hovering unrelated element should hide pop-up after delay');
-},`hovering the pop-up keeps it from being hidden`);
-
-promise_test(async (t) => {
-  await mouseOver(unrelated);
-  const popUp = document.getElementById('example1');
-  const invoker = document.getElementById('invoker1');
-  assert_false(popUp.matches(':top-layer'));
-  await mouseOver(invoker);
-  await waitForHoverTime(hoverWaitTime);
-  assert_true(popUp.matches(':top-layer'));
-  await waitForHoverTime(hoverWaitTime);
-  assert_true(popUp.matches(':top-layer'),'While still hovering the invoker, pop-up should not be hidden');
-  await mouseOver(popUp);
-  await waitForHoverTime(hoverWaitTime);
-  await mouseOver(invoker);
-  await waitForHoverTime(hoverWaitTime);
-  assert_true(popUp.matches(':top-layer'),'Moving hover between invoker and pop-up should keep pop-up from being hidden');
-  await mouseOver(unrelated);
-  await waitForHoverTime(hoverWaitTime);
-  assert_false(popUp.matches(':top-layer'),'Moving hover to unrelated should finally hide the pop-up');
-},`hovering a popuphovertarget invoking element keeps the pop-up from being hidden`);
-</script>
-
-<div popup id=example2>Pop-up</div>
-<button popuptoggletarget=example2><span><span data-note=nested_element id=invoker2>Click me</span></span></button>
-
-<script>
-promise_test(async (t) => {
-  await mouseOver(unrelated);
-  const popUp = document.getElementById('example2');
-  const invoker = document.getElementById('invoker2');
-  assert_equals(getComputedStyleTimeMs(popUp,'popUpHideDelay'),hoverDelays,'pop-up-hide-delay is incorrect');
-  assert_false(popUp.matches(':top-layer'));
-  await mouseOver(invoker);
-  popUp.showPopUp();
-  await waitForHoverTime(hoverWaitTime);
-  assert_true(popUp.matches(':top-layer'),'While hovering an invoker element, pop-up should not be hidden');
-  await mouseOver(popUp);
-  await waitForHoverTime(hoverWaitTime);
-  await mouseOver(invoker);
-  await waitForHoverTime(hoverWaitTime);
-  assert_true(popUp.matches(':top-layer'),'Moving hover between invoker and pop-up should keep pop-up from being hidden');
-  await mouseOver(unrelated);
-  await waitForHoverTime(hoverWaitTime);
-  assert_false(popUp.matches(':top-layer'),'Moving hover to unrelated should finally hide the pop-up');
-},`hovering a popuptoggletarget invoking element keeps the pop-up from being hidden`);
-</script>
diff --git a/html/semantics/popups/popup-popuphovertarget-attribute.tentative.html b/html/semantics/popups/popup-popuphovertarget-attribute.tentative.html
deleted file mode 100644
index e845b0d49df5f4..00000000000000
--- a/html/semantics/popups/popup-popuphovertarget-attribute.tentative.html
+++ /dev/null
@@ -1,169 +0,0 @@
-<!DOCTYPE html>
-<meta charset="utf-8" />
-<title>The popuphovertarget attribute</title>
-<link rel="author" href="mailto:masonf@chromium.org">
-<link rel=help href="https://open-ui.org/components/popup.research.explainer">
-<meta name="timeout" content="long">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="/resources/testdriver.js"></script>
-<script src="/resources/testdriver-actions.js"></script>
-<script src="/resources/testdriver-vendor.js"></script>
-<script src="resources/popup-utils.js"></script>
-
-<body>
-<style>
-.unrelated {top:0;}
-.invoker {top:100px; width:fit-content; height:fit-content;}
-[popup] {top: 200px;}
-.offset-child {top:300px; left:300px;}
-</style>
-
-<script>
-const popUpShowDelay = 100; // The CSS delay setting.
-const hoverWaitTime = 200; // How long to wait to cover the delay for sure.
-let nextId = 0;
-async function makePopUpAndInvoker(test, popUpType, invokerType, delayMs) {
-  delayMs = delayMs || popUpShowDelay;
-  const popUp = Object.assign(document.createElement('div'),{popUp: popUpType, id: `pop-up-${nextId++}`});
-  document.body.appendChild(popUp);
-  popUp.textContent = 'Pop-up';
-  let invoker = document.createElement('div');
-  invoker.setAttribute('class','invoker');
-  invoker.setAttribute('popuphovertarget',popUp.id);
-  invoker.setAttribute('style',`pop-up-show-delay: ${delayMs}ms; pop-up-hide-delay: 1000s;`);
-  document.body.appendChild(invoker);
-  const actualHoverDelay = Number(getComputedStyle(invoker)['popUpShowDelay'].slice(0,-1))*1000;
-  assert_equals(actualHoverDelay,delayMs,'pop-up-show-delay is incorrect');
-  const originalInvoker = invoker;
-  const reassignPopupFn = (p) => originalInvoker.setAttribute('popuphovertarget',p.id);
-  switch (invokerType) {
-    case 'plain':
-      // Invoker is just a div.
-      invoker.textContent = 'Invoker';
-      break;
-    case 'nested':
-      // Invoker is just a div containing a div.
-      const child1 = invoker.appendChild(document.createElement('div'));
-      child1.textContent = 'Invoker';
-      break;
-    case 'nested-offset':
-      // Invoker is a child of the element wearing the 'popuphovertarget' attribute,
-      // and is not contained within the bounds of the popuphovertarget element.
-      invoker.textContent = 'Invoker';
-      // Reassign invoker to the child:
-      invoker = invoker.appendChild(document.createElement('div'));
-      invoker.textContent = 'Invoker child';
-      invoker.setAttribute('class','offset-child');
-      break;
-    case 'none':
-      // No invoker.
-      invoker.remove();
-      break;
-    default:
-      assert_unreached(`Invalid invokerType ${invokerType}`);
-  }
-  const unrelated = document.createElement('div');
-  document.body.appendChild(unrelated);
-  unrelated.textContent = 'Unrelated';
-  unrelated.setAttribute('class','unrelated');
-  test.add_cleanup(async () => {
-    popUp.remove();
-    invoker.remove();
-    originalInvoker.remove();
-    unrelated.remove();
-    await waitForRender();
-  });
-  await mouseOver(unrelated); // Start by mousing over the unrelated element
-  await waitForRender();
-  return {popUp,invoker,reassignPopupFn};
-}
-
-// NOTE about testing methodology:
-// This test checks whether pop-ups are triggered *after* the appropriate hover
-// delay. The delay used for testing is kept low, to avoid this test taking too
-// long, but that means that sometimes on a slow bot/client, the hover delay can
-// elapse before we are able to check the pop-up status. And that can make this
-// test flaky. To avoid that, the msSinceMouseOver() function is used to check
-// that not-too-much time has passed, and if it has, the test is simply skipped.
-
-["auto","hint","manual"].forEach(type => {
-  ["plain","nested","nested-offset"].forEach(invokerType => {
-    promise_test(async (t) => {
-      const {popUp,invoker} = await makePopUpAndInvoker(t,type,invokerType);
-      assert_false(popUp.matches(':top-layer'));
-      await mouseOver(invoker);
-      let showing = popUp.matches(':top-layer');
-      // See NOTE above.
-      if (msSinceMouseOver() < popUpShowDelay)
-        assert_false(showing,'pop-up should not show immediately');
-      await waitForHoverTime(hoverWaitTime);
-      assert_true(msSinceMouseOver() >= hoverWaitTime,'waitForHoverTime should wait the specified time');
-      assert_true(popUp.matches(':top-layer'),'pop-up should show after delay');
-      assert_true(hoverWaitTime > popUpShowDelay,'popUpShowDelay is the CSS setting, hoverWaitTime should be longer than that');
-      popUp.hidePopUp(); // Cleanup
-    },`popuphovertarget attribute shows a pop-up with popup=${type}, invokerType=${invokerType}`);
-
-    promise_test(async (t) => {
-      const longerHoverDelay = hoverWaitTime*2;
-      const {popUp,invoker} = await makePopUpAndInvoker(t,type,invokerType,longerHoverDelay);
-      await mouseOver(invoker);
-      let showing = popUp.matches(':top-layer');
-      // See NOTE above.
-      if (msSinceMouseOver() >= longerHoverDelay)
-        return; // The WPT runner was too slow.
-      assert_false(showing,'pop-up should not show immediately');
-      await waitForHoverTime(hoverWaitTime);
-      showing = popUp.matches(':top-layer');
-      if (msSinceMouseOver() >= longerHoverDelay)
-        return; // The WPT runner was too slow.
-      assert_false(showing,'pop-up should not show after not long enough of a delay');
-    },`hoverpopup pop-up-show-delay is respected (popup=${type}, invokerType=${invokerType})`);
-
-    promise_test(async (t) => {
-      const {popUp,invoker} = await makePopUpAndInvoker(t,type,invokerType);
-      popUp.showPopUp();
-      assert_true(popUp.matches(':top-layer'));
-      await mouseOver(invoker);
-      assert_true(popUp.matches(':top-layer'),'pop-up should stay showing on mouseover');
-      await waitForHoverTime(hoverWaitTime);
-      assert_true(popUp.matches(':top-layer'),'pop-up should stay showing after delay');
-      popUp.hidePopUp(); // Cleanup
-    },`popuphovertarget attribute does nothing when pop-up is already showing (popup=${type}, invokerType=${invokerType})`);
-
-    promise_test(async (t) => {
-      const {popUp,invoker} = await makePopUpAndInvoker(t,type,invokerType);
-      await mouseOver(invoker);
-      let showing = popUp.matches(':top-layer');
-      popUp.remove();
-      // See NOTE above.
-      if (msSinceMouseOver() >= popUpShowDelay)
-        return; // The WPT runner was too slow.
-      assert_false(showing,'pop-up should not show immediately');
-      await waitForHoverTime(hoverWaitTime);
-      assert_false(popUp.matches(':top-layer'),'pop-up should not show even after a delay');
-      // Now put it back in the document and make sure it doesn't trigger.
-      document.body.appendChild(popUp);
-      await waitForHoverTime(hoverWaitTime);
-      assert_false(popUp.matches(':top-layer'),'pop-up should not show even when returned to the document');
-    },`popuphovertarget attribute does nothing when pop-up is moved out of the document (popup=${type}, invokerType=${invokerType})`);
-
-    promise_test(async (t) => {
-      const {popUp,invoker,reassignPopupFn} = await makePopUpAndInvoker(t,type,invokerType);
-      const popUp2 = Object.assign(document.createElement('div'),{popUp: type, id: 'foobar'});
-      document.body.appendChild(popUp2);
-      t.add_cleanup(() => popUp2.remove());
-      await mouseOver(invoker);
-      let eitherShowing = popUp.matches(':top-layer') || popUp2.matches(':top-layer');
-      reassignPopupFn(popUp2);
-      // See NOTE above.
-      if (msSinceMouseOver() >= popUpShowDelay)
-        return; // The WPT runner was too slow.
-      assert_false(eitherShowing,'pop-up should not show immediately');
-      await waitForHoverTime(hoverWaitTime);
-      assert_false(popUp.matches(':top-layer'),'pop-up #1 should not show since popuphovertarget was reassigned');
-      assert_false(popUp2.matches(':top-layer'),'pop-up #2 should not show since popuphovertarget was reassigned');
-    },`popuphovertarget attribute does nothing when target changes (popup=${type}, invokerType=${invokerType})`);
-  });
-});
-</script>
