Add x64 build support to automate.py.

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk@1409 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Add x64 build support to automate.py.

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk@1411 5089003a-bbd8-11dd-ad1f-f1f9622dbc98