Updates gen_skp_ranges.py on recent changes of bench names, storage locations, etc.

Updates gen_skp_ranges.py on recent changes of bench names, storage locations, etc.
Sample command: bench/gen_skp_ranges.py -r 7621:7621
It is slow due to cloud storage slowness. You can download the bench logs using gsutil and set the -d flag to make it super fast.
Committed: https://code.google.com/p/skia/source/detail?r=7629

[robertphillips, 2013-02-06 20:50:29]

LGTM