Remove deprecated aura_shell_unittests target

Remove deprecated aura_shell_unittests target

This target has been renamed to ash_unittests.  We were
temporarily building ash_unittests and copying it to
aura_shell_unittests.  The buildbots have been reconfigured
and restarted, so they should look for the new name.  We
can now eliminate the copy step and the old target.

BUG=110107
TEST=green buildbots


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=150578

[James Cook, 2012-07-30 18:38:32]

Peter, PTAL.

Sky, I need OWNERS approval for the ash/ change.

[James Cook, 2012-07-30 20:33:03]

Dan, can I get OWNERS approval for the ash/ change?  Sky seemed to be at a FE/UI
summit today and tomorrow.

[Daniel Erat, 2012-07-30 20:45:37]

LGTM

(Wow, I didn't even know that the renaming had finally happened!)

[Peter Mayo, 2012-07-30 23:02:39]

LGTM

[commit-bot: I haz the power, 2012-08-08 15:53:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jamescook@chromium.org/10828075/10001

[commit-bot: I haz the power, 2012-08-08 17:27:20]

Change committed as 150578

[James Cook, 2012-08-08 20:54:09]

This landed and appears to have stuck.  After a month of waiting (and 7 months
since the bug was filed), this cleanup is done!