Roll src/third_party/shaderc/src 821d564bc789..873d0470b40d (1 commits)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/821d564bc789..873d0470b40d

git log 821d564bc789..873d0470b40d --date=short --first-parent --format='%ad %ae %s'
2020-01-29 kainino1@gmail.com Make a source_set for libshaderc_spvc (#976)

Created with:
  gclient setdep -r src/third_party/shaderc/src@873d0470b40d

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

Bug: None
Tbr: radial-bots+chrome-roll@google.com
Change-Id: I2eb8ab67eacae0f4fa2e76ea9f6c42e3e218e48d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2026999Reviewed-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@{#736230}

DEPS

@@ -304,7 +304,7 @@ 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': '821d564bc7896fdd5d68484e10aac30ea192568f',
+  'shaderc_revision': '873d0470b40d85a2b14ecce83a7484d62728941a',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.