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/filters/alphabeticalattributes.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/filters/alphabeticalattributes.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/filters/alphabeticalattributes.py b/third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/filters/alphabeticalattributes.py
new file mode 100644
index 0000000000000000000000000000000000000000..fed6996c1d9b0dcc5462f3e1cc8e4e153cb414ce
--- /dev/null
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/thirdparty/wpt/wpt/tools/html5lib/html5lib/filters/alphabeticalattributes.py
@@ -0,0 +1,20 @@
+from __future__ import absolute_import, division, unicode_literals
+
+from . import _base
+
+try:
+    from collections import OrderedDict
+except ImportError:
+    from ordereddict import OrderedDict
+
+
+class Filter(_base.Filter):
+    def __iter__(self):
+        for token in _base.Filter.__iter__(self):
+            if token["type"] in ("StartTag", "EmptyTag"):
+                attrs = OrderedDict()
+                for name, value in sorted(token["data"].items(),
+                                          key=lambda x: x[0]):
+                    attrs[name] = value
+                token["data"] = attrs
+            yield token