Follow-up to https://codereview.chromium.org/291993003/

Follow-up to https://codereview.chromium.org/291993003/

r271506 removed has_sse2 from the gcc file, but it remained in the tsan
header.

(I asked in
https://codereview.chromium.org/10948035/diff/17001/base/atomicops_internals_tsan.h#newcode24
for why this struct is in this file at all.)

BUG=348761, 94925
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=277909

[Mark Mentovai, 2014-06-17 19:43:06]

LGTM

[Nico, 2014-06-17 19:51:24]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2014-06-17 19:53:32]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thakis@chromium.org/345453002/1

[commit-bot: I haz the power, 2014-06-17 23:57:07]

Change committed as 277909