DevTools: migrate inspector-protocol/dom tests to a new test runner

third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getFlattenedDocument.js

Index: third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getFlattenedDocument.js
diff --git a/third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getFlattenedDocument.js b/third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getFlattenedDocument.js
new file mode 100644
index 0000000000000000000000000000000000000000..0226158d39f162e010746c4b65574ca9b397a1cb
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/inspector-protocol/dom/dom-getFlattenedDocument.js
@@ -0,0 +1,15 @@
+(async function(testRunner) {
+  var {page, session, dp} = await testRunner.startURL('resources/dom-getFlattenedDocument.html', '');
+
+  await session.evaluate(() => {
+    var host = document.querySelector('#shadow-host').createShadowRoot();
+    var template = document.querySelector('#shadow-template');
+    host.appendChild(template.content);
+    template.remove();
+  });
+  dp.DOM.enable();
+  var response = await dp.DOM.getFlattenedDocument({depth: -1, pierce: true});
+  testRunner.logMessage(response.result);
+  testRunner.completeTest();
+})
+