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

third_party/WebKit/LayoutTests/imported/web-platform-tests/dom/nodes/attributes.js

-function attr_is(attr, v, ln, ns, p, n) {
-  assert_equals(attr.value, v)
-  assert_equals(attr.nodeValue, v)
-  assert_equals(attr.textContent, v)
-  assert_equals(attr.localName, ln)
-  assert_equals(attr.namespaceURI, ns)
-  assert_equals(attr.prefix, p)
-  assert_equals(attr.name, n)
-  assert_equals(attr.nodeName, n);
-  assert_equals(attr.specified, true)
-}
-
-function attributes_are(el, l) {
-  for (var i = 0, il = l.length; i < il; i++) {
-    attr_is(el.attributes[i], l[i][1], l[i][0], (l[i].length < 3) ? null : l[i][2], null, l[i][0])
-    assert_equals(el.attributes[i].ownerElement, el)
-  }
-}