SkXPS: new document API.

Now requires a IXpsOMObjectFactory pointer.  This will allow sandboxing
to be used in Chromium.  (Chrome will create a IXpsOMObjectFactory, then
go into sandbox mode, then call SkDocumenent::MakeXPS().)

Change-Id: Ic4b48d4b148c44e188d12a9481fb74735546528a
Reviewed-on: https://skia-review.googlesource.com/8052
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
6 files changed