Clarify artifact documentation for test results

This clarifies the meaning of forward slashes in artifact file paths,
and also clarifies the directory these paths are relative to, when no
artifact permanent location is set.

Bug: 775619
Change-Id: I1f41d86273455123823350a39b239cc04b6a0216
Reviewed-on: https://chromium-review.googlesource.com/802092
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521525}
1 file changed