mozilla/servo — pull request #1533 by metajack (2014-01-23 00:04:32+00:00)
Title: Change `get_attr()` to `get_attr_val_for_layout()`.

The old code was used by both layout and script, but was erroneously
borrowing for the layout case (which causes parallelism
problems). script now uses only `value_ref()` or `get_attribute()`, and
layout now has its own unsafe version that dances around the borrows of
`@mut Attr`.