It's somewhat annoying to have the script delete your toolchain
directory (at least during testing) and it necessitates downloading
3-4G to restore, so add a short timeout before doing so.

Also, hide the output of taskkill'ing mspdbsrv so that the first message
isn't '''ERROR: The process "..." not found.'''.

R=maruel@chromium.org
BUG=323300

Review URL: https://codereview.chromium.org/146583012

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@251084 0039d316-1c4b-4281-b951-d872f2087c98