OS X Yosemite freezes randomly, absolutely everything hangs (screen, trackpad, keyboard, sound, applications, rtc.)
As you can see in this snippet, it is stuck with the

/Library/LaunchAgents/com.oracle.java.Java-Updater.plist, error = 2: No such file or directory


Try to repair it by running Java Update.

If that does not help you need to repair your installation using the Command R.