The Go 1.5 version of the standard library's encoding/xml package was
rolled back to the 1.4 behavior. See #11841

Change-Id: I5a5d6636b90b19d59dbcfdc44adf54b4f0b3ccb7
Reviewed-on: https://go-review.googlesource.com/12772Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>