[telemetry] Add --output option to output results to a file

R=tonyg
NOTRY=True

Review URL: https://chromiumcodereview.appspot.com/11875008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@176566 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed