Remove DEPRECATED_beginRecording(). This removes: 1) ability to record old pictures with SkPictureRecorder; 2) a couple tests specific to the old backend. The functionality of DEPRECATED_beginRecording() now lives in (private) SkPicture::Backport(), which is the only place we need it now. BUG=skia: TBR=reed@google.com Review URL: https://codereview.chromium.org/618303002