Don't emit a default namespace declaration if it's already the default

Don't emit a default namespace declaration if it's already the default

If an element declares a new default namespace (has an xmlns="..."
attribute) make sure said namespace is used to update the namespace-table.
This avoids having to emit a default namespace declaration for descendants
of said element.

BUG=340794
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=168672

[adamk, 2014-03-06 19:23:08]

lgtm

[fs, 2014-03-06 19:29:19]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2014-03-06 19:29:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/fs@opera.com/184633007/1

[commit-bot: I haz the power, 2014-03-06 20:03:21]

Change committed as 168672