An emerging story for General Motors (GM) - Get Report is the turn in its China business, says TheStreet's Jim Cramer. GM's net income doubled, and it's revenue surged to a record. General Motors attributed some of the gains to a surge in sales in China. Cramer says he's watching closely what happens with China sales for U.S. companies, since Caterpillar (CAT) - Get Report also mentioned strength in China when it reported earnings. Cramer made the comments from the floor of the New York Stock Exchange.