+ // Parses a Retry-After header that is either an absolute date/time or a
+ // number of seconds in the future. Interprets absolute times as relative to
+ // |now|. If |retry_after_string| is successfully parsed and indicates a time
+ // that is not in the past, fills in |*retry_after| and returns true;
+ // otherwise, returns false.
+ static bool ParseRetryAfterHeader(const std::string& retry_after_string,
+ base::Time now,
+ base::TimeDelta* retry_after);
+