GitLab

This should have been working already, but a functioning
crash_reporter::CrashReporterClient::GetCrashMetricsLocation() for macOS
was unintentionally absent.

BUG=crashpad:100,chromium:678720

Review-Url: https://codereview.chromium.org/2610883006
Cr-Commit-Position: refs/heads/master@{#442888}