This is the first step to address http://crbug.com/23131 by creating
a series of V8 ConsStrings as more data arrives from the server.

Review URL: http://codereview.chromium.org/271085

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3066 ce2b1a6d-e550-0410-aec6-3dcde31c8c00