Gene Barr, President and CEO of the Pennsylvania Chamber of Business and Industry, will be among those watching Governor Tom Wolf deliver his annual proposal for the new state budget.   Last year,  Mr. Barr says the governor proposed changes to the corporate tax structure that would have been a disadvantage for the state's businesses.    Already this year, the governor has renewed his call, for the fifth time,  for a tax on Marcellus shale natural gas drillers.