Builder:
https://uberchromegw.corp.google.com/i/chromeos.chrome/builders/amd64-generic%20Trusty%20%28Informational%29/builds/54249

Log:
/mnt/data/b/build/slave/chrome-tot-chromeos-amd64-generic-trusty/build/src/buildtools/linux64/gn gen //out_amd64-generic/Release --check
  -> returned 1
ERROR at //build/config/compiler/compiler.gni:115:3: Assertion failed.
  assert(is_win_fastlink || !use_goma,
  ^-----
Goma builds that use symbol_level 2 must use is_win_fastlink.
See //BUILD.gn:11:1: whence it was imported.
import("//build/config/compiler/compiler.gni")
^--------------------------------------------
GN gen failed: 1
step returned non-zero exit code: 1
@@@STEP_FAILURE@@@

Suspicious CL: https://codereview.chromium.org/2661023010

I'll revert the CL.