Currently viewport bot data are only available for Android bots.
Please go to http://go/skia-buildbot to pick a green revision (-r) for an Android platform (-p). This can take a few minutes because Google Storage stores files in a flat structure instead of in directories.
Alternatively, download the bot data of interest into a local directory (or generate them from your machine) and set the script to read from there (-d).
Review URL: https://codereview.appspot.com/7093065
git-svn-id: http://skia.googlecode.com/svn/trunk@7729 2bbb7eff-a529-9590-31e7-b0007b416f81
