Gerald E. Johnston, 58, chairman and chief executive of Clorox Co., has suffered a heart attack late Wednesday afternoon. The thoughts and support of our entire company are with Jerry and his family at this time,” Robert W. Matschullat, presiding director of the company’s board of directors, said in a statement. The company has an emergency succession plan that could be put in place any time, but officials have not considered it necessary to take that step, explai...