remove esprima export boilerplate

R=arv
BUG=

Review URL: https://codereview.appspot.com/10361043

third_party/esprima/esprima.js

@@ -30,19 +30,7 @@
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-(function (root, factory) {
-    'use strict';
-
-    // Universal Module Definition (UMD) to support AMD, CommonJS/Node.js,
-    // Rhino, and plain browser loading.
-    if (typeof define === 'function' && define.amd) {
-        define(['exports'], factory);
-    } else if (typeof exports !== 'undefined') {
-        factory(exports);
-    } else {
-        factory((root.esprima = {}));
-    }
-}(this, function (exports) {
+(function (global) {
     'use strict';
 
     var Token,
@@ -1207,5 +1195,7 @@
         return parseProgram();
     }
 
-    exports.parse = parse;
-}));
+    global.esprima = {
+        parse: parse
+    };
+})(this);