CPU profile code and Heap Snapshot code are completely unrelated to each other.
So we can extract heap snapshot part into separate file.
No functional changes.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/12314027

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13706 ce2b1a6d-e550-0410-aec6-3dcde31c8c00