We have a problem with really big apps. The snapshot for such pages doesn't fit into JS heap on DevTools front-end side. I'd like to move the snapshot's nodes data into Int32Array.
This will reduce the pressure. At this moment it is not possible because the snapshot uses uint64_t for ids.

BUG=none
TEST=profiler-generator tests

Review URL: https://chromiumcodereview.appspot.com/9617006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10996 ce2b1a6d-e550-0410-aec6-3dcde31c8c00