Roll src/third_party/skia 3517aa7b14ad..a5909925e3a8 (2 commits)

https://skia.googlesource.com/skia.git/+log/3517aa7b14ad..a5909925e3a8

git log 3517aa7b14ad..a5909925e3a8 --date=short --first-parent --format='%ad %ae %s'
2019-12-11 herb@google.com Remove unused buffer call for SkGlyphRunPaint
2019-12-11 mtklein@google.com roll clang to 9.0

Created with:
  gclient setdep -r src/third_party/skia@a5909925e3a8

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 djsollen@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: djsollen@google.com
Change-Id: I8df1ca9a5de3df24c328e22b999d63683be57f67
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1963142Reviewed-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@{#724069}

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': '3517aa7b14ad52aa662bf38932f2ba358a9f8318',
+  'skia_revision': 'a5909925e3a8514ceb837320aad66cf38879065f',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.