GitLab

The bugs fixed are:
- programs required for -o2 weren't checked for when using -o2
but were checked for lower -o levels.
- if no savings could be found the results printed at the end
were confusing and the script had a divide by zero error.

BUG=None

Review URL: https://chromiumcodereview.appspot.com/15970004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@203051 0039d316-1c4b-4281-b951-d872f2087c98