kjellander 6aeef74b6e Remove uses of #pragma once and add PRESUBMIT check.
They violate the C++ coding style guide:
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md#File-headers

BUG=webrtc:7191
NOTRY=True

Review-Url: https://codereview.webrtc.org/2707843002
Cr-Commit-Position: refs/heads/master@{#16712}
2017-02-20 09:13:18 +00:00
..
2017-02-14 12:58:56 +00:00
2017-02-14 12:58:56 +00:00
2016-11-16 19:11:38 +00:00