Update web-platform-tests and CSS tests.

- Update CSS tests to revision e05bfd5e30ed662c2f8a353577003f8eed230180.
- Update web-platform-tests to revision a052787dd5c069a340031011196b73affbd68cd9.

tests/wpt/web-platform-tests/tools/manifest/utils.py

@@ -1,8 +1,7 @@
+import platform
 import os
-from six import BytesIO
 
-blacklist = ["/tools/", "/resources/", "/common/", "/conformance-checkers/", "/_certs/"]
-blacklist_in = ["/resources/", "/support/"]
+from six import BytesIO
 
 def rel_path_to_url(rel_path, url_base="/"):
     assert not os.path.isabs(rel_path)
@@ -12,23 +11,22 @@ def rel_path_to_url(rel_path, url_base="/"):
         url_base += "/"
     return url_base + rel_path.replace(os.sep, "/")
 
-def is_blacklisted(url):
-    if "/" not in url[1:]:
-        return True
-    for item in blacklist:
-        if url.startswith(item):
-            return True
-    for item in blacklist_in:
-        if item in url:
-            return True
-    return False
 
 def from_os_path(path):
-    return path.replace(os.path.sep, "/")
+    assert os.path.sep == "/" or platform.system() == "Windows"
+    rv = path.replace(os.path.sep, "/")
+    if "\\" in rv:
+        raise ValueError("path contains \\ when separator is %s" % os.path.sep)
+    return rv
+
 
 def to_os_path(path):
+    assert os.path.sep == "/" or platform.system() == "Windows"
+    if "\\" in path:
+        raise ValueError("normalised path contains \\")
     return path.replace("/", os.path.sep)
 
+
 class ContextManagerBytesIO(BytesIO):
     def __enter__(self):
         return self
@@ -36,6 +34,7 @@ class ContextManagerBytesIO(BytesIO):
     def __exit__(self, *args, **kwargs):
         self.close()
 
+
 class cached_property(object):
     def __init__(self, func):
         self.func = func