Roll src/third_party/skia 6e6b4dd7d3e2..7e2dea568299 (3 commits)

https://skia.googlesource.com/skia.git/+log/6e6b4dd7d3e2..7e2dea568299

git log 6e6b4dd7d3e2..7e2dea568299 --date=short --first-parent --format='%ad %ae %s'
2019-12-19 mtklein@google.com SkColorFilter::onProgram()
2019-12-19 bsalomon@google.com GrGLSLShaderBuilder::appendTextureLookupAndBlend
2019-12-19 fmalita@chromium.org [skottie] Treat unknown effects as warnings

Created with:
  gclient setdep -r src/third_party/skia@7e2dea568299

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 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

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
Bug: None
Tbr: borenet@google.com
Change-Id: I651c8c88a914d86517f69190758f7d070cf368c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1977340Reviewed-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@{#726645}

DEPS

@@ -175,7 +175,7 @@ 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': '6e6b4dd7d3e20c698517ad193d47565eb1c803a5',
+  'skia_revision': '7e2dea568299f3e49fc0edbd8b851562e8666275',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.