Please refer to link:
It’s probably too late for your presentation, but this might help others.
You need to set your virtual network adapter to the “e1000″ type by adding the line
NOTE: The above line should work for Fusion as well.
In order fix no connection available for Chromium OS Vanilla
1. Power down virtual machine.
2. browse to virtual machine folder.
3. Hold shit & Right click on your chrome virtual machine
4. Select Open with notepad
5. Scroll to the bottom of the text file and paste the following
ethernet0.virtualDev = “e1000″
6. Save and exit notepad
This should fix your ethernet issue.
If this doesn’t work go back to virtual machine in notepad look for the following line
ethernet0.virtualDev = “vlance”
Delete that line and save notepad again. Make sure Virtual Machine network adapter is set to bridged not Nat. You can now login and have internet access.
Good Luck to all