Fix the single page version of cocos2d-js-tests til the point that PerformanceSpriteTest can be run.

This is accompanied by a [pull request](https://github.com/cocos2d/cocos2d-js-tests/pull/186) to `cocos2d-js-tests`.

This change follows some of the guideline in [Understanding the Restrictions Imposed by the Closure Compiler](https://developers.google.com/closure/compiler/docs/limitations) (the part saying **Using string names to refer to object properties** and **Referring to variables as properties of the global object** are dangerous).