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