Add context to shaper.

This allows correct shaping across any run breaks.

Change-Id: Ib305bd974ccee2471b1dfe8bd895fb28e475177f
Reviewed-on: https://skia-review.googlesource.com/145726
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
1 file changed