crosh: network_diagnostics: Add option to disable logging

BUG=chromium-os:22084
TEST=Rerun with and without new "--no-log" argument, test to make sure
Downloads has no new content with this argument set.

Change-Id: I44e8fac88019fe9a603379ebcadd52afa8d5b7be
Reviewed-on: http://gerrit.chromium.org/gerrit/10682
Reviewed-by: Sam Leffler <sleffler@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
1 file changed