Roll skia c22498502cda..6447a1a77738 (1 commits)

https://skia.googlesource.com/skia.git/+log/c22498502cda..6447a1a77738

git log c22498502cda..6447a1a77738 --date=short --no-merges --format='%ad %ae %s'
2019-09-16 nigeltao@google.com Remove a deprecated Wuffs io_buffer::reader call

Created with:
  gclient setdep -r skia@6447a1a77738

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-skiabot-test-autoroll
Please CC borenet@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

Bug: None
TBR=borenet@google.com
Change-Id: I126f36d4f6c7937ba2fe69e004e272c8254ba49d
Reviewed-on: https://skia-review.googlesource.com/c/skiabot-test/+/241780
Reviewed-by: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
diff --git a/DEPS b/DEPS
index 7d73d44..f8b7a74 100644
--- a/DEPS
+++ b/DEPS
@@ -3,7 +3,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.
-  'skia_revision': 'c22498502cda8f3f295f19f0824f0580109b2acb',
+  'skia_revision': '6447a1a77738bbd6f67e2290924018f9c85e7327',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.