Revert "Require V8 to be explicitly initialized before an Isolate is created"

LOG=n
TBR=svenpanne@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/582953002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24055 ce2b1a6d-e550-0410-aec6-3dcde31c8c00