Reject shaders that invoke functions hidden by variable or struct name. BUG=22 Review URL: http://codereview.appspot.com/1855057
Reject shaders that invoke functions hidden by variable or struct name.
BUG=22
Review URL: http://codereview.appspot.com/1855057

csulmone/angle,csulmone/angle,csulmone/angle,csulmone/angle