Clean up layout 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 99 matching lines @@
     let startingNode = nodes[label];
     for (let node = startingNode; node; node = node.parentNode) {
       if (attachedNodes.indexOf(node) >= 0)
         continue;
       let id = node.id;
       if (!id)
         continue;
       attachedNodes.push(node);
       node.addEventListener(event.type, (e) => {
         log.push([id,
-                  event.relatedTarget ? labelFor(event.relatedTarget) : null,
-                  event.composedPath().map((n) => {
+                  e.relatedTarget ? labelFor(e.relatedTarget) : null,
+                  e.composedPath().map((n) => {
                     return labelFor(n);
                   })]);
       });
     }
   }
   target.dispatchEvent(event);
   return log;
 }
 
 function dispatchUAEventWithLog(nodes, target, eventType, callback) {
 
   function labelFor(e) {
     return e.id || e.tagName;
   }
 
   let log = [];
   let attachedNodes = [];
   for (let label in nodes) {
     let startingNode = nodes[label];
     for (let node = startingNode; node; node = node.parentNode) {
       if (attachedNodes.indexOf(node) >= 0)
         continue;
       let id = node.id;
       if (!id)
         continue;
       attachedNodes.push(node);
       node.addEventListener(eventType, (e) => {
         log.push([id,
-                  event.relatedTarget ? labelFor(event.relatedTarget) : null,
-                  event.composedPath().map((n) => {
+                  e.relatedTarget ? labelFor(e.relatedTarget) : null,
+                  e.composedPath().map((n) => {
                     return labelFor(n);
                   })]);
       });
     }
   }
   callback(target);
   return log;
 }
 
 // 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');
   }
 }