Re-enable session_restore on mac

Re-enable session_restore on mac

BUG=511273
CQ_EXTRA_TRYBOTS=tryserver.chromium.perf:linux_perf_bisect;tryserver.chromium.perf:mac_perf_bisect

Committed: https://crrev.com/9bfbd07e4c4a190c0348b37e2848c7d06d6ac19f
Cr-Commit-Position: refs/heads/master@{#339702}

[sullivan, 2015-07-21 13:44:16]

sullivan@chromium.org changed reviewers:
+ erikchen@chromium.org, nednguyen@chromium.org

[nednguyen, 2015-07-21 15:02:13]

nednguyen@google.com changed reviewers:
+ nednguyen@google.com

[nednguyen, 2015-07-21 15:02:13]

lgtm

[sullivan, 2015-07-21 15:03:12]

The CQ bit was checked by sullivan@chromium.org

[commit-bot: I haz the power, 2015-07-21 15:03:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250453005/20001

[commit-bot: I haz the power, 2015-07-21 17:05:04]

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

[commit-bot: I haz the power, 2015-07-21 17:05:05]

Try jobs failed on following builders:
  android_nexus5_perf_bisect on tryserver.chromium.perf (JOB_TIMED_OUT, no build
URL)

[sullivan, 2015-07-21 17:07:03]

The CQ bit was checked by sullivan@chromium.org

[commit-bot: I haz the power, 2015-07-21 17:07:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250453005/20001

[commit-bot: I haz the power, 2015-07-21 18:22:21]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-21 18:23:50]

Patchset 2 (id:??) landed as
https://crrev.com/9bfbd07e4c4a190c0348b37e2848c7d06d6ac19f
Cr-Commit-Position: refs/heads/master@{#339702}