Adding missing include guard to test header file.

Found when experimenting with jumbo compilation for mojo
generated files.

Change-Id: I202a22fa9aa24df3f928992b67e3ad35321e7e1c
Reviewed-on: https://chromium-review.googlesource.com/693254
Reviewed-by: Ken Rockot <rockot@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#506085}

CrOS-Libchrome-Original-Commit: 9c0e4bd2bd737b4905d0b69c572869b21bef0756
1 file changed
tree: c4d1523f815015011a5506acbb70cae231968cc8
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/