Add html5lib to the list of modules in webkitpy/thirdparty/wpt/wpt/tools.

third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/treewalkers/pulldom.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/treewalkers/pulldom.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/treewalkers/pulldom.py b/third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/treewalkers/pulldom.py
new file mode 100644
index 0000000000000000000000000000000000000000..0b0f515fec7e48ea063ca2b6ed95e3bf26c2d612
--- /dev/null
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/treewalkers/pulldom.py
@@ -0,0 +1,63 @@
+from __future__ import absolute_import, division, unicode_literals
+
+from xml.dom.pulldom import START_ELEMENT, END_ELEMENT, \
+    COMMENT, IGNORABLE_WHITESPACE, CHARACTERS
+
+from . import _base
+
+from ..constants import voidElements
+
+
+class TreeWalker(_base.TreeWalker):
+    def __iter__(self):
+        ignore_until = None
+        previous = None
+        for event in self.tree:
+            if previous is not None and \
+                    (ignore_until is None or previous[1] is ignore_until):
+                if previous[1] is ignore_until:
+                    ignore_until = None
+                for token in self.tokens(previous, event):
+                    yield token
+                    if token["type"] == "EmptyTag":
+                        ignore_until = previous[1]
+            previous = event
+        if ignore_until is None or previous[1] is ignore_until:
+            for token in self.tokens(previous, None):
+                yield token
+        elif ignore_until is not None:
+            raise ValueError("Illformed DOM event stream: void element without END_ELEMENT")
+
+    def tokens(self, event, next):
+        type, node = event
+        if type == START_ELEMENT:
+            name = node.nodeName
+            namespace = node.namespaceURI
+            attrs = {}
+            for attr in list(node.attributes.keys()):
+                attr = node.getAttributeNode(attr)
+                attrs[(attr.namespaceURI, attr.localName)] = attr.value
+            if name in voidElements:
+                for token in self.emptyTag(namespace,
+                                           name,
+                                           attrs,
+                                           not next or next[1] is not node):
+                    yield token
+            else:
+                yield self.startTag(namespace, name, attrs)
+
+        elif type == END_ELEMENT:
+            name = node.nodeName
+            namespace = node.namespaceURI
+            if name not in voidElements:
+                yield self.endTag(namespace, name)
+
+        elif type == COMMENT:
+            yield self.comment(node.nodeValue)
+
+        elif type in (IGNORABLE_WHITESPACE, CHARACTERS):
+            for token in self.text(node.nodeValue):
+                yield token
+
+        else:
+            yield self.unknown(type)