Delete MacVDA from the codebase since it is dead code and not being worked on.

http://crbug.com/133828#c36 summarizes why this wasn't turned on.
Also related: http://openradar.appspot.com/radar?id=1845403 

BUG=133828

Review URL: https://chromiumcodereview.appspot.com/14401013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@196621 0039d316-1c4b-4281-b951-d872f2087c98
16 files changed