Fix error in running update.py

The new JS compiler web service is pickier about global.
This was built using a private install of yuicompressor-2.4.7.
Verified that systrace still generates valid .html.

Bug: 6825749
Change-Id: I3023bb7950d90636ad1906f2b8ac497aa4d22d84
diff --git a/src/shared/js/util.js b/src/shared/js/util.js
index c77fc34..f975ff8 100644
--- a/src/shared/js/util.js
+++ b/src/shared/js/util.js
@@ -7,7 +7,7 @@
  * @type {!Object}
  * @const
  */
-var global = this;
+//var global = this;
 
 /**
  * Alias for document.getElementById.