Update endRecordingAsPicture to finishRecordingAsPicture

BUG=skia:

DOCS_PREVIEW= https://skia.org/?cl=8854

Change-Id: Ia3ad32d088d44fbe47ec37de016931c4bd21231c
Reviewed-on: https://skia-review.googlesource.com/8854
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>
2 files changed