First and foremost, please let me know if creating a new question would be 'better' than updating this question. Anyway... I am currently running Antergos and I am experiencing the same problems. Hal doesn't seem to work and o tried installing an older version to no avail. I am interested in trying to get my 'hands' on a ChromeOS recovery so I can extract its flash player.
To find out if you can play DRM content (from Adobe's help page):
Go to the url in (1) and paste the url in (2) into the "Input the Video URL" bar.
I upgraded to Linux Mint 17 a couple weeks ago. Prior to that, I was running on LM 16 and had an issue playing protected content on Google Chrome. I fixed that issue after installing hal and disabling Chrome's flash player in favour of Adobe's. But since I'm on LM 17, that problem reared its ugly head again. I recently installed hal and since Chrome no longer gave me the option to disable/enable specific flash plug-ins, I renamed Adobe's to libpepflashplayer and moved it to opt/google/chrome/PepperFlash. Unfortunately, the problem still persists and it's worse now since I know get the notice "Could not load Shockwave Flash."
Linux Mint 17 (64)
Google Chrome Version 35.0.1916.114
Sites attempted to access: Espn3.com, Video.adultswim.com/watch-live