More OStreamsUse OStreams more often.

This is a mostly mechanical CL (more than 90% Emacs macros and
query-replace-regexp) moving FILE*/StringStream*-based APIs to
OStream-based APIs. There are a few places where this had to stop,
otherwise the CL would be even bigger, but this can easily and
incrementally cleaned up later.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/363323003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22232 ce2b1a6d-e550-0410-aec6-3dcde31c8c00