The firm will also cover any losses sustained by the franchise in the first few years, according to Sports Business Journal.
Longtime NFL reporter John Clayton believes the Chargers and Rams will end up in the Los Angeles area.
The vote fast-tracks construction by allowing the city to avoid a public vote and long environmental review.
The resolution states the city is "fully committed' to keeping the Chargers in San Diego.
Linebacker Jarret Johnson played 12 seasons in the NFL.
"Everywhere I walk around town, that's what I hear: 'Help the Chargers stay here.'"