You code only works for browsers that support WOFF for downloadable fonts. This is a direct consequence of just ripping off some code sent by the Google server to some browser. The Google server sends different CSS code to different browsers, and your code breaks this. Moreover, there is no guarantee that the URLs will keep working. URLs like http://themes.googleusercontent.com/static/fonts/chivo/v4/uOXSiKkEygwkvR4cgUzOz_esZW2xOQ-xsNqO47m55DA.woff should not be expected to be stable, and Google has made no statement about supporting the use of such URLs.
You can proceed with the rip-off strategy, with its drawbacks, by simply viewing, in your browser, the CSS code of a page. For example, on Firefox, you could use the Web Developer Extension, which has a command for viewing all CSS files for a page. Then you would copy the content of the relevant CSS file.
A better approach—assuming you don’t want to use fonts as hosted by Google—is to download the font files from Google (the Google Web Fonts pages have an interface for that, too, though they keep telling you don’t need to use it) and then generate the various font formats and a CSS file e.g. with FontSquirrel WebFont Generator. The results may differ from those you get by using Google-hosted fonts; Google does not disclose exactly how their font files have been generated.