Analytics does track clicks, impressions, and earnings for your AdSense for content ad units. This includes both text and image ads shown through AdSense for content.
Analytics does not track search boxes or any other AdSense products. Additionally, if you serve AdSense through an ad server (such as Google Ad Manager), your Analytics reports may not include impressions and clicks for ads served through an ad server.
Note: If you call a local copy of ga.js or urchin.js, you may be invalidating AdSense reporting in Analytics. Calling a locally stored copy of the Analytics code means referencing a saved version of the urchin.js or ga.js tracking script on your web server, rather than calling it from Google (as implemented in the code given in your Analytics account). For example, if your website is www.example.com and you call www.example.com/urchin.js in your Analytics implementation, you are using a local (rather than Google-hosted) copy of the Analytics tracking code, which may prevent Analytics from tracking AdSense clicks and impressions.