[html-tests] Added test for Element's custom attributes (#1440)

Based on a discussion in [1], this tests ensures that Element's dataset
properties does not interfere with namespaced attributes with the same
name, but in different namespaces (in the former case, all Element's
dataset properties are stored as attributes with no namespace).

[1] https://critic.hoppipolla.co.uk/showcomment?chain=8907

View on GitHub: https://github.com/w3c/web-platform-tests/pull/1440

Received on Wednesday, 3 December 2014 16:14:06 UTC