Roll src/third_party/shaderc/src f28d5287c68b..c4835b8523b1 (1 commits)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/f28d5287c68b..c4835b8523b1

git log f28d5287c68b..c4835b8523b1 --date=short --no-merges --format='%ad %ae %s'
2019-10-19 9856269+sarahM0@users.noreply.github.com spvc: add known_spvc_failures  (#842)

Created with:
  gclient setdep -r src/third_party/shaderc/src@c4835b8523b1

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

TBR=radial-bots+chrome-roll@google.com

Bug: None
Change-Id: Ib8e8e98e2fc096c4815ac8e59c8ea82a34b95fb1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1869822Reviewed-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@{#707659}

DEPS

@@ -298,7 +298,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
-  'shaderc_revision': 'f28d5287c68b526e61e4f3c4b6098e751b4b5b6d',
+  'shaderc_revision': 'c4835b8523b129ed035a8c61e3e0e843600aa308',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.