Rewrite and organize tests in LayoutTests/shadow-dom

third_party/WebKit/LayoutTests/shadow-dom/resources/shadow-dom.js

 function removeWhiteSpaceOnlyTextNodes(node)
 {
     for (var i = 0; i < node.childNodes.length; i++) {
         var child = node.childNodes[i];
         if (child.nodeType === Node.TEXT_NODE && child.nodeValue.trim().length == 0) {
             node.removeChild(child);
             i--;
         } else if (child.nodeType === Node.ELEMENT_NODE || child.nodeType === Node.DOCUMENT_FRAGMENT_NODE) {
             removeWhiteSpaceOnlyTextNodes(child);
         }
@@ skipping 54 matching lines @@
     return node;
 }
 
 function createTestTree(node) {
 
   let ids = {};
 
   function attachShadowFromTemplate(template) {
     let parent = template.parentNode;
     parent.removeChild(template);
-    let shadowRoot = parent.attachShadow({mode: template.getAttribute('data-mode')});
+    let shadowRoot;
+    if (template.getAttribute('data-mode') === 'v0') {
+      // For legacy Shadow DOM
+      shadowRoot = parent.createShadowRoot();
+    } else {
+      shadowRoot = parent.attachShadow({mode: template.getAttribute('data-mode')});
+    }
     let id = template.id;
     if (id) {
       shadowRoot.id = id;
       ids[id] = shadowRoot;
     }
     shadowRoot.appendChild(document.importNode(template.content, true));
     return shadowRoot;
   }
 
   function walk(root) {
@@ skipping 65 matching lines @@
                   e.composedPath().map((n) => {
                     return labelFor(n);
                   })]);
       });
     }
   }
   callback(target);
   return log;
 }
 
+function makeExpectedEventPathLog(path) {
+  let expectedLog = [];
+  for (let i of path) {
+    expectedLog.push([i, null, path]);
+  }
+  return expectedLog;
+}
+
+function debugEventLog(log) {
+  for (let i = 0; i < log.length; i++) {
+    console.log('[' + i + '] currentTarget: ' + log[i][0] + ' relatedTarget: ' + log[i][1] + ' composedPath(): ' + log[i][2]);
+  }
+}
+
+function debugCreateTestTree(nodes) {
+  for (let k in nodes) {
+    console.log(k + ' -> ' + nodes[k]);
+  }
+}
+
 // This function assumes that testharness.js is available.
 function assert_event_path_equals(actual, expected) {
   assert_equals(actual.length, expected.length);
   for (let i = 0; i < actual.length; ++i) {
     assert_equals(actual[i][0], expected[i][0], 'currentTarget at ' + i + ' should be same');
     assert_equals(actual[i][1], expected[i][1], 'relatedTarget at ' + i + ' should be same');
     assert_array_equals(actual[i][2], expected[i][2], 'composedPath at ' + i + ' should be same');
   }
 }