Roll src/third_party/skia 6b921b7e4add..942d69fa9d5f (3 commits)

https://skia.googlesource.com/skia.git/+log/6b921b7e4add..942d69fa9d5f

git log 6b921b7e4add..942d69fa9d5f --date=short --no-merges --format='%ad %ae %s'
2019-09-20 ethannicholas@google.com Revert "Fixed GLSL ES compilation error in GLTestAtlasTextRenderer"
2019-09-20 ethannicholas@google.com Fixed GLSL ES compilation error in GLTestAtlasTextRenderer
2019-09-20 bsalomon@google.com Check for scratch textures in GrResourceProvider.

Created with:
  gclient setdep -r src/third_party/skia@942d69fa9d5f

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 brianosman@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=brianosman@google.com

Bug: chromium:1005237
Change-Id: I4b656d62de889c974622d551cc7cb73cea34fb44
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815831Reviewed-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@{#698657}

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': '6b921b7e4add9e48561b2659b6e594397271bed9',
+  'skia_revision': '942d69fa9d5febb0ec99cd3fa7814be186a44b5d',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.