The test was trying to solve this problem already with AutoThread, but
the order of variable declaration was causing it to be created after
"rtc::Thread::Current()" was already called.
BUG=chromium:701262
TBR=pbos@webrtc.org
Review-Url: https://codereview.webrtc.org/2858343002
Cr-Commit-Position: refs/heads/master@{#18019}