HOUSTON—Perhaps the most stressful part for Los Angeles Rams coach Sean McVay was wondering if maybe he took Matthew Stafford out a bit too soon in a rout of the Houston Texans. Stafford threw for 305 yards and three touchdowns in three quarters, and the Rams dominated the inept Texans in every way in a 38-22 win Sunday. The Rams had a 38-0 lead when McVay pulled the veteran quarterback. “Our coaches will tell you it’s a champagne problem to be in those spots,” McVay said. “But that’s usually when I am the biggest basket case because it’s how do you really manage it?” It’s the fourth straight victory for the Rams (7-1) and the seventh loss in a row for the Texans (1-7), their longest skid since dropping the final 14 games of the 2013 season. Stafford threw an 11-yard touchdown pass to Cooper Kupp with about 9½ minutes …