tree a5808215c0bf3cd6da7520511f99fdf1ba294551
parent 86cedfc315886037a0fba6d72ba53bf47bd0b539
author Robert Phillips <robertphillips@google.com> 1482184313 -0500
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1482255639 +0000

Fix mapping from src to dst image space in SkAlphaThresholdFilter

This CL does 3 things:
   It updates the imagealphathreshold GMs so they would've caught this bug
   It updates SkAlphaImageThresholdFilter to fix the bug
   It updates the imagealphathreshold_surface GM to match the imagealphathreshold_crop GM (which it was, presumably, originally written to do)

The bug in question is that the prior mapping from src to dst space was correct as long as the imageOffset was (0, 0).

BUG=675332

Change-Id: I3aa1f463a2234576fb2277797caa2fc4aba2650d
Reviewed-on: https://skia-review.googlesource.com/6291
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Stephan White <senorblanco@chromium.org>
Commit-Queue: Robert Phillips <robertphillips@google.com>