[DevTools] Move inspector-protocol/accessibility tests to new harness

third_party/WebKit/LayoutTests/inspector-protocol/accessibility/accessibility-ignoredNodesModal.js

+(async function(testRunner) {
+  let {page, session, dp} = await testRunner.startHTML(`
+    <style>
+    body.done * {
+      display: none;
+    }
+    </style>
+    <div data-dump>Hidden by modal dialog</div>
+    <dialog data-dump>
+        (Dialog itself is not hidden)
+        <div data-dump>Non-hidden element inside dialog</div>
+    </dialog>
+  `, '');
+
+  var dumpAccessibilityNodesBySelectorAndCompleteTest =
+      (await testRunner.loadScript('../resources/accessibility-dumpAccessibilityNodes.js'))(testRunner, session);
+
+  await session.evaluate('document.querySelector("dialog").showModal();');
+  var msg = await dp.DOM.getDocument();
+  dumpAccessibilityNodesBySelectorAndCompleteTest('[data-dump]', false, msg);
+})