sudo apt-add-repository ppa:skunk/pepper-flash
sudo apt-get update
sudo apt-get install pepflashplugin-installer
luego
sudo vi /etc/chromium-browser/default
y anades esto al final
CHROMIUM_FLAGS="$CHROMIUM_FLAGS --ppapi-flash-path=/usr/lib/pepflashplugin-installer/libpepflashplayer.so --ppapi-flash-version=$FLASH_VERSION"