Roll src/third_party/skia 76500e5d0a62..6d1c0d4196f1 (2 commits)

https://skia.googlesource.com/skia.git/+log/76500e5d0a62..6d1c0d4196f1

git log 76500e5d0a62..6d1c0d4196f1 --date=short --no-merges --format='%ad %ae %s'
2019-09-05 michaelludwig@google.com Avoid use of SkMatrixImageFilter to handle CTM for backdrop filtering
2019-09-05 csmartdalton@google.com Rename GrGLIRect to GrNativeRect

Created with:
  gclient setdep -r src/third_party/skia@6d1c0d4196f1

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-autoroll
Please CC jlavrova@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

CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux-blink-rel;luci.chromium.try:linux-chromeos-compile-dbg;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
TBR=jlavrova@google.com

Bug: None
Change-Id: I26af2651e1f91914a6cf035eb4876a1d11686471
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1787852Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#693906}

DEPS

@@ -162,7 +162,7 @@ vars = {
   # 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': '76500e5d0a62ef44fd9e5da3a091e7cff0796732',
+  'skia_revision': '6d1c0d4196f19537cc64f74bacc7d123de3be454',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.