Prepare push to trunk.  Now working on version 3.21.14.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/23994004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16633 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
some random isolate threading

R=svenpanne@chromium.org
BUG=

Review URL: https://codereview.chromium.org/23494046

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16636 ce2b1a6d-e550-0410-aec6-3dcde31c8c00