This tutorial is only for USING AoB not finding one yourself.
To simplify things up, use firefox instead of chrome or IE (if ever possible) as firefox use a different executable name for flash player container that is very advantageous to recognize.

Here is the video tutorial for firefox
http://www.youtube.com/watch?v=g9sxj_ZSwBA

For unity player, you will have an extra plugin-container.exe if you have some flash object running(maybe advertisments), so totally 2 plugin-container.exe
Select the newest one, newly opened executable will have the lowest position when choosing executable in cheat engine, so scroll down until you find the lowest plugin-container.exe