Renamed GetMessage into GetNextMessage.

Renamed GetMessage into GetNextMessage.

Windows defines GetMessage as GetMessageW.
This makes linking fail if p224_spake included after windows headers.

NOPRESUBMIT=true

Committed: https://crrev.com/d120360c6836854d4536969df71a1ca3b0d4073e
Cr-Commit-Position: refs/heads/master@{#313782}

[Vitaly Buka (NO REVIEWS), 2015-01-29 19:03:47]

vitalybuka@chromium.org changed reviewers:
+ agl@chromium.org, wez@chromium.org

[Wez, 2015-01-29 19:10:59]

The CQ bit was checked by wez@chromium.org

[Wez, 2015-01-29 19:11:00]

lgtm

[commit-bot: I haz the power, 2015-01-29 19:12:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/889663003/1

[agl, 2015-01-29 19:12:43]

lgtm

[commit-bot: I haz the power, 2015-01-29 20:50:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-29 20:52:21]

Patchset 1 (id:??) landed as
https://crrev.com/d120360c6836854d4536969df71a1ca3b0d4073e
Cr-Commit-Position: refs/heads/master@{#313782}