Add an HTMLElement with popover and ToggleEvent to idlharness

See [1] and [2] for details. Since the Popover API spec PR landed, the
[1] PR (once it lands) will bring in all of the popover-related IDL.
This CL just ensures that an element with the popover attribute, plus
the ToggleEvent, are added to the html/dom/idlharness.https.html test
harness. I also verified that once [1] lands, the additional tests
run, and that the coverage of the APIs stays the same as the
html/semantics/popovers/idlharness.html file being removed.

[1] https://github.com/web-platform-tests/wpt/pull/38345/files
[2] https://chromium-review.googlesource.com/c/chromium/src/+/4245778

Bug: 1307772
Change-Id: If13762b8a062a9e40f566d4524b0af00225a6535
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4247069
Commit-Queue: Mason Freed <masonf@chromium.org>
Auto-Submit: Mason Freed <masonf@chromium.org>
Reviewed-by: Joey Arhar <jarhar@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1105150}
diff --git a/html/dom/idlharness.https.html b/html/dom/idlharness.https.html
index 56b4a0c..4e9e25f 100644
--- a/html/dom/idlharness.https.html
+++ b/html/dom/idlharness.https.html
@@ -59,7 +59,10 @@
       Transferable: [],
       Document: ['iframe.contentDocument', 'new Document()', 'documentWithHandlers'],
       XMLDocument: ['document.implementation.createDocument(null, "", null)'],
-      HTMLElement: ['document.createElement("noscript")'], // more tests in html/semantics/interfaces.js
+      HTMLElement: [
+        'document.createElement("noscript")',
+        'Object.assign(document.createElement("noscript"),{popover:"auto"})',
+      ], // more tests in html/semantics/interfaces.js
       HTMLUnknownElement: ['document.createElement("bgsound")'], // more tests in html/semantics/interfaces.js
       HTMLHtmlElement: ['document.createElement("html")'],
       HTMLHeadElement: ['document.createElement("head")'],
@@ -125,6 +128,7 @@
       CanvasRenderingContext2D: ['document.createElement("canvas").getContext("2d")'],
       CanvasGradient: [],
       CanvasPattern: [],
+      ToggleEvent: ['new ToggleEvent("beforetoggle")'],
       TextMetrics: [],
       ImageData: ['new ImageData(10, 10)'],
       HTMLMapElement: ['document.createElement("map")'],
diff --git a/html/semantics/popovers/idlharness.html b/html/semantics/popovers/idlharness.html
deleted file mode 100644
index c28d49d..0000000
--- a/html/semantics/popovers/idlharness.html
+++ /dev/null
@@ -1,54 +0,0 @@
-<!DOCTYPE HTML>
-<meta charset="utf-8">
-<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=/resources/WebIDLParser.js></script>
-<script src=/resources/idlharness.js></script>
-
-<div id=p1 popover></div>
-<div id=p2 popover=auto></div>
-<div id=p3 popover=manual></div>
-<button id=b1 popovertoggletarget=p1></button>
-<button id=b2 popoverhidetarget=p2></button>
-<button id=b3 popovershowtarget=p3></button>
-<input id=i1 type=button popovertoggletarget=p1></input>
-<input id=i2 type=button popoverhidetarget=p2></input>
-<input id=i3 type=button popovershowtarget=p3></input>
-
-<script type="module">
-'use strict';
-
-idl_test(
-  ['popover'],
-  ['html','dom'],
-  idl_array => {
-    idl_array.add_objects({
-      HTMLElement: [
-        'document.getElementById("p1")',
-        'document.getElementById("p2")',
-        'document.getElementById("p3")',
-      ],
-      HTMLInputElement: [
-        'document.getElementById("i1")',
-        'document.getElementById("i2")',
-        'document.getElementById("i3")',
-      ],
-      HTMLButtonElement: [
-        'document.getElementById("b1")',
-        'document.getElementById("b2")',
-        'document.getElementById("b3")',
-      ],
-      BeforeToggleEvent: [
-        'new ToggleEvent("beforetoggle")',
-        'new ToggleEvent("beforetoggle", {oldState: "open"})',
-        'new ToggleEvent("beforetoggle", {oldState: "open",newState: "open"})',
-        'new ToggleEvent("toggle")',
-        'new ToggleEvent("toggle", {oldState: "open"})',
-        'new ToggleEvent("toggle", {oldState: "open",newState: "open"})',
-      ],
-    });
-  }
-);
-</script>
diff --git a/interfaces/popover.idl b/interfaces/popover.idl
deleted file mode 100644
index 4e8c85f..0000000
--- a/interfaces/popover.idl
+++ /dev/null
@@ -1,25 +0,0 @@
-partial interface HTMLElement {
-  undefined togglePopover(optional boolean force);
-  undefined showPopover();
-  undefined hidePopover();
-  [CEReactions] attribute DOMString? popover;
-};
-
-interface mixin PopoverTargetElement {
-  [CEReactions] attribute Element? popoverToggleTargetElement;
-  [CEReactions] attribute Element? popoverHideTargetElement;
-  [CEReactions] attribute Element? popoverShowTargetElement;
-};
-HTMLInputElement includes PopoverTargetElement;
-HTMLButtonElement includes PopoverTargetElement;
-
-interface ToggleEvent : Event {
-    constructor(DOMString type, optional ToggleEventInit eventInitDict = {});
-    readonly attribute DOMString oldState;
-    readonly attribute DOMString newState;
-};
-
-dictionary ToggleEventInit : EventInit {
-    DOMString oldState = "";
-    DOMString newState = "";
-};