Removed some unused variables in Windows code.

Removed some unused variables in Windows code.

Note: Regarding the ICMP6_CLOSE_FUNC variable in winping.cc,
Icmp6CloseHandle does not exist, and IcmpCloseHandle is the correct way
to close an IPv6 handle. Therefore the existing code is correct to use
close_ on both types of connections and this variable is unnecessary.

BUG=505319
Committed: https://crrev.com/e987a47f95abc4fe9ea649cf9e70eaf30175f813
Cr-Commit-Position: refs/heads/master@{#9555}

[Matt Giuca, 2015-07-09 00:40:48]

mgiuca@chromium.org changed reviewers:
+ sergeyu@chromium.org

[Matt Giuca, 2015-07-09 00:40:49]

Copy of https://codereview.webrtc.org/1214713005/ but landing on the right base
URL this time.

[Matt Giuca, 2015-07-09 00:40:50]

Copy of https://codereview.webrtc.org/1214713005/ but landing on the right base
URL this time.

[Sergey Ulanov, 2015-07-09 00:44:45]

lgtm

[Matt Giuca, 2015-07-09 00:59:12]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2015-07-09 00:59:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1231653003/1

[Matt Giuca, 2015-07-09 00:59:35]

Thanks! (Now we'll see if the CQ works here, otherwise I'll git cl land.)

[commit-bot: I haz the power, 2015-07-09 01:44:31]

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

[commit-bot: I haz the power, 2015-07-09 01:44:33]

Try jobs failed on following builders:
  linux_msan on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/linux_msan/builds/3587)

[Matt Giuca, 2015-07-09 07:25:34]

Looks like this test was designed to be flaky...

[Matt Giuca, 2015-07-09 07:25:39]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2015-07-09 07:25:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1231653003/1

[commit-bot: I haz the power, 2015-07-09 07:53:59]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-09 07:54:11]

Patchset 1 (id:??) landed as
https://crrev.com/e987a47f95abc4fe9ea649cf9e70eaf30175f813
Cr-Commit-Position: refs/heads/master@{#9555}