Replace Position::fEndOffset with fLength.

In a followup, this will make it easier to save memory.

Change-Id: I33e9838d1b3170362f4e7c58ba5f60a1928a4b55
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/533698
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2 files changed