Move SkOSFile.h to src/core

Skia needs implementations (ports) of the declarations in this header,
but no one outside of Skia the library should use them.

Change-Id: I1b92eca787a61892d7b3c0ac8c5996774429ae24
Reviewed-on: https://skia-review.googlesource.com/9878
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
2 files changed