Roll Skia from 74470aec5185 to 3b5a4fac1e5e (6 revisions)

https://skia.googlesource.com/skia.git/+log/74470aec5185..3b5a4fac1e5e

2020-07-13 brianosman@google.com Use stable sort for Viewer's help screen
2020-07-13 herb@google.com improve the speed of empty GrTextBlobs
2020-07-13 herb@google.com move drawTextPaths from RTC to SubRun
2020-07-13 johnstiles@google.com Replace ModulateRGBA effect with Xfermode using modulate blend.
2020-07-13 johnstiles@google.com Replace ModulateAlpha effect with Xfermode using src-in blend.
2020-07-13 brianosman@google.com SkRuntimeEffect: Guard against programs with no "main"

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 nifong@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/+doc/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: nifong@google.com
Change-Id: I9387a27f796d01c683716051f946b6d92caf1e0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2295423Reviewed-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@{#787852}

DEPS

@@ -194,7 +194,7 @@ 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': '74470aec5185086a2f7d7182c0397ebe7763aeb9',
+  'skia_revision': '3b5a4fac1e5e5c15af2adc56aa7c19d6f6043274',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.