Defines don't need ; to end the statement.

src/renderers/webgl/WebGLProgram.js

@@ -255,15 +255,15 @@ function generatePrecision( parameters ) {
 
 	if ( parameters.precision === "highp" ) {
 
-		precisionstring += "\n#define HIGH_PRECISION;";
+		precisionstring += "\n#define HIGH_PRECISION";
 
 	} else if ( parameters.precision === "mediump" ) {
 
-		precisionstring += "\n#define MEDIUM_PRECISION;";
+		precisionstring += "\n#define MEDIUM_PRECISION";
 
 	} else if ( parameters.precision === "lowp" ) {
 
-		precisionstring += "\n#define LOW_PRECISION;";
+		precisionstring += "\n#define LOW_PRECISION";
 
 	}