Reland Safebrowsing: allow sending enhanced download protection pings on OSX.

Reland Safebrowsing: allow sending enhanced download protection pings on OSX.

The re-land fixes the unittests to test with/without the field trial set.

Sending is controlled by a finch experiment.

The verdict from the server is ignored for now.

BUG=413967
Committed: https://crrev.com/c682493aea96e57a0bd759867f5813ec2486f0cc
Cr-Commit-Position: refs/heads/master@{#295227}

[mattm, 2014-09-17 02:30:49]

Patchset #1 (id:1) has been deleted

[mattm, 2014-09-17 02:32:15]

mattm@chromium.org changed reviewers:
+ noelutz@chromium.org

[noé, 2014-09-17 02:34:45]

lgtm

[mattm, 2014-09-17 02:48:47]

The CQ bit was checked by mattm@chromium.org

[commit-bot: I haz the power, 2014-09-17 02:49:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/580593003/40001

[commit-bot: I haz the power, 2014-09-17 04:27:51]

Committed patchset #2 (id:40001) as 9d85e6e61d8538f2931ab5a185f8ac06691a380f

[commit-bot: I haz the power, 2014-09-17 04:28:44]

Patchset 2 (id:??) landed as
https://crrev.com/c682493aea96e57a0bd759867f5813ec2486f0cc
Cr-Commit-Position: refs/heads/master@{#295227}