Use RunShellWithReturnCode() instead RunShell() to allow uploads of empty base files with git (issue 11718).
Use RunShellWithReturnCode() instead RunShell() to allow uploads of
empty base files with git (issue 11718).

nicko96/Chrome-Infra,nicko96/Chrome-Infra,riannucci/rietveldv2,nicko96/Chrome-Infra,nicko96/Chrome-Infra,riannucci/rietveldv2,nicko96/Chrome-Infra