gistfile1.txt

Dual booting chromium with up to date flash. (Or 'buntu derivatives, I used xubuntu). I sincerely hope this saves somebody the grief I had to go through to get it right.  

I used 3 usb keys.  One for Ubuntu, one for gparted live, and one for chromium.  This document assumes you've booted to chromium from usb to assure it works and assumes you know how to make bootable USB's. (or that you at least know how to use google). 

Method A (Tested, works)
Get a gparted iso & boot from it - usb or cd.  (google can help you with this). If you've borked the drive, rewrite the boot sector.  (failed chromium installs for instance). Get a chromium ISO and write it to USB.  (I used dd). Insert it & refresh gparted.  Copy the State Partition (big one) to the first partition on the drive, make it bigger if you want.  Grab the root-a partition (other big one) and make it the second.  Create a swap partion 1024 - 2048 - megabyte-ish at the end of the drive.  Make an ext4 partition with whatever is left in between.  Reboot to the Ubuntu CD.  Follow int install, choose custom partitioning, choose the big ext4 as your "/" and the swap as, well, you get the idea.  Let it install grub, reboot and goto NEXT. 

Method B (Untested). 
Get a gparted iso & boot from it - usb or cd. Resize existing Ubuntu upwards.  Warning: No matter what file I edit, chrome always seems to rewrite the first partition.  If Ubuntu is there, it will ruin it. You can try editing files to tell it where the state partition is but, be warned, it didn't work for me.  Copy the State Partition to the first partition on the drive, make it bigger if you want.  Grab the root partition and make it the second.  Reboot to a grub repair CD and repair grub.  Should work, in theory. 

NEXT: (vim if you know it)
sudo nano /etc/grub.d/40_custom
add:
menuentry "Chromium OS" {
savedefault
insmod ext2
set root='(hd0,2)'
linux /boot/vmlinuz quiet console=tty2 init=/sbin/init boot=local rootwait ro noresume noswap loglevel=1 noinitrd root=/dev/sda2 i915.modeset=1 cros_efi cros_debug
}
at the end, and save it.  run sudo update-grub2. 

Make grub prettier:
Next, install grub-customizer.  (google it - no use writing a howto when better ones are out there)  Delete the extra kernel, the extra options, leave memtest(or delete it, I don’t care), delete the “detected linux”  Move chromium (or ubuntu, I don’t care) to the top.  Personally, I like to leave just two options - ubuntu and chromium.  Also, I like to change my timeout to 3 seconds, but I do this by hand.  (You can probably do it from grub-customizer, but don't know where)
sudo vim /etc/default/grub
GRUB_TIMEOUT="3"
sudo update-grub2. 

FLASH!
BEWARE - following other instructions is a good way to ruin things that currently work.  Don't mess with other plugins. 

This is done FROM Ubuntu, where it's much easier.  (or xubuntu, or lubuntu, ect). 
Step 1.  Get pepper
sudo apt-get install pepperflashplugin-nonfree
Surprisingly enough, you don’t need chromium-web, but you can install it if you want.

Step 2.  Get files:
dan@dan-Parrot:~$ mkdir temp
dan@dan-Parrot:~$ cd temp
dan@dan-Parrot:~/temp$ wget --no-check-certificate -O "data.tar" "https://googledrive.com/host/0B78S5hOqFxkOOGpDSHp4YWt0REU/addons.tar"
dan@dan-Parrot:~/temp$ tar -xf data.tar
dan@dan-Parrot:~/temp$ cd data
There are only 2 files you need - do NOT mess with any others - you have been warned. 

Step 3.  Install them
Mount ROOT-A (click on it in file manager)
dan@dan-Parrot:~/temp/data$ 
sudo mkdir /media/dan/ROOT-A/opt/google/chrome/pepper
sudo cp manifest.json /media/dan/ROOT-A/opt/google/chrome/pepper
sudo cp pepper-flash.info /media/dan/ROOT-A/opt/google/chrome/pepper
sudo cp /usr/lib/pepperflashplugin-nonfree/libpepflashplayer.so /media/dan/ROOT-A/opt/google/chrome/pepper/

Reboot to chrome and you should have the latest flash, even though the plugins page will say it is older.  You should be able to do "sudo update-pepperflashplugin-nonfree -- install" and recopy as needed. 

How to update?
Haven't tried - probably copy over the partitions again.  I would not do a power wash nor a command line upgrade - they will most probably ruin your ubuntu.