Chrome is chromium on linux (ubuntu 12.04) Many online solutions link java sun, but this example is for openjdk:
sudo apt-get install icedtea-7-plugin
http://java.com/en/download/testjava.jsp # approve it in the browser, approve it in the java popup
if you haven't already: sudo update-java-alternatives -s java-1.7.0-openjdk-amd64
these steps below are unnecessary
sudo su
ls -ahl /usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64 | grep -i plugin
notice, no plugin, do the install above, then you should see IcedTeaPlugin.so
cd /usr/lib/chromium-browser/plugins
ln -s /usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64 IcedTeaPlugin.so