How do you play RuneScape on Google Chrome?

Java

The same as on any other browser. Go to the RuneScape Web site, and start playing. (RuneScape requires Java; on some computers that may cause problems on some browsers. In this case, try using a different browser.)

Edit: Agreed. I've found that even updating the Java client doesn't make a bit of difference when playing it on google Chrome. Mozilla Firefox runs it the best because of data compression. If you don't want to change your browser to play, download RuneScape to your computer so you can play it without a browser, directly over your internet connection.