Example failing build:
https://ci.chromium.org/buildbot/chromium.clang/ToTWinThinLTO64/1788

Logs:
https://logs.chromium.org/v/?s=chromium%2Fbb%2Fchromium.clang%2FToTWinThinLTO64%2F1788%2F%2B%2Frecipes%2Fsteps%2Ftest_installer%2F0%2Fstdout

Excerpt:
======================================================================
ERROR: ChromeUserLevel: no_pv -> install_chrome_user -> chrome_user_installed_not_inuse -> test_chrome_with_chromedriver_user -> chrome_user_installed_not_inuse -> uninstall_chrome_user -> clean
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\b\c\b\ToTWinThinLTO64\src\chrome\test\mini_installer\test_installer.py", line 156, in runTest
    self._config.actions[action], self._variable_expander)
  File "C:\b\c\b\ToTWinThinLTO64\src\chrome\test\mini_installer\test_installer.py", line 231, in RunCommand
    expanded_command, returncode))
Exception: Command python test_chrome_with_chromedriver.py --chromedriver-path="C:\b\c\b\ToTWinThinLTO64\src\out\Release_x64\chromedriver.exe"  "C:\Users\chrome-bot\AppData\Local\Google\Chrome\Application\chrome.exe" returned non-zero exit status 1