Move the html directory from web-platform-tests/ to wpt/.

third_party/WebKit/LayoutTests/imported/wpt/html/semantics/tabular-data/html-table-section-element.js

 // https://html.spec.whatwg.org/multipage/#dom-tbody-rows
 function testRowsAttribute(localName) {
   var elem = document.createElement(localName);
   assert_equals(elem.rows.length, 0);
 
   // Child <p> should *not* count as a row
   elem.appendChild(document.createElement("p"));
   assert_equals(elem.rows.length, 0);
 
   // Child <tr> should count as a row
   var childTr = document.createElement("tr");
   elem.appendChild(childTr);
   assert_equals(elem.rows.length, 1);
 
   // Nested table with child <tr> should *not* count as a row
   var nested = document.createElement(localName);
   nested.appendChild(document.createElement("tr"));
   var nestedTable = document.createElement("table");
   nestedTable.appendChild(nested);
   childTr.appendChild(nestedTable);
   assert_equals(elem.rows.length, 1);
 }