Flash games and alt-tabbing

2 instances in particular

1. Town of Salem(steam game)

2. League of legends character select

Situation.

1. I am in game everythnig is working fine

2. I alt tab and watch a youtube video

3. game freezes and becomes unresponsive

Note* If youtube is playing in background before playing game no effect but the moment I alt tab it will freeze.

I believe both of these games work off of flash and I know youtube videos are flash. This makes me suspect flash could possibly be the issue but it may be something else.

In town of salem the countdown will continue until it hits 0 I wont see chat change or anything

In league of legends the champ select countdown of the current champ will count down to 0 and I wont see it move onto the next player. Youtube doesn't crash at all.