Do not use sub-pixel positioning for source space

Since the source space drawing modes call getGlyphMetrics with
the point {0, 0}, just turn of sub-pixel positioning. This uses
a more efficient code path in the strike

Change-Id: I360f56e1eede776dfa82db6b780b88c1fda50d36
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206701
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
Auto-Submit: Herb Derby <herb@google.com>
3 files changed