google/oauth2client — pull request #11 by craigcitro (2014-05-19 21:44:10+00:00)
Title: Retry on throttled credentials refresh requests.

PTAL @wonderfly and @skelterjohn

This adds throttled retries when the actual credential refresh fails due to rate limits. (This can happen for boring internal reasons, and will eventually go away.) We have external customers hitting this currently, so a fix seems warranted.