Add barriers to atomic utils.

Add barriers to atomic utils.

Loads get an acquire, store/cas a release. Increment gets a full barrier.

R=hpayer@chromium.org
BUG=

Committed: https://crrev.com/4d6c4a3e22dadaab89a1fded92a0423b1ca9f035
Cr-Commit-Position: refs/heads/master@{#30751}

[Michael Lippautz, 2015-09-15 13:49:22]

mlippautz@chromium.org changed reviewers:
+ hpayer@chromium.org

[Michael Lippautz, 2015-09-15 13:49:22]

PTAl; this should meet our expectations now

[Hannes Payer (out of office), 2015-09-15 14:06:14]

lgtm

[Michael Lippautz, 2015-09-15 14:06:47]

The CQ bit was checked by mlippautz@chromium.org

[commit-bot: I haz the power, 2015-09-15 14:06:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1343883004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1343883004/1

[commit-bot: I haz the power, 2015-09-15 14:10:42]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-15 14:10:43]

Try jobs failed on following builders:
  v8_linux_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_rel/builds/9621)

[Michael Lippautz, 2015-09-15 14:20:10]

The CQ bit was checked by mlippautz@chromium.org

[Michael Lippautz, 2015-09-15 14:20:10]

The patchset sent to the CQ was uploaded after l-g-t-m from hpayer@chromium.org
Link to the patchset: https://codereview.chromium.org/1343883004/#ps20001
(title: "Fix test expectations")

[commit-bot: I haz the power, 2015-09-15 14:20:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1343883004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1343883004/20001

[commit-bot: I haz the power, 2015-09-15 14:58:52]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-15 14:59:00]

Patchset 2 (id:??) landed as
https://crrev.com/4d6c4a3e22dadaab89a1fded92a0423b1ca9f035
Cr-Commit-Position: refs/heads/master@{#30751}