Roll shaderc from 702723ac7599 to 8c2ca20216be (1 revision)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/702723ac7599..8c2ca20216be

2020-12-09 rharrison@google.com Rolling 5 dependencies (#1161)

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/+doc/master/autoroll/README.md

Tbr: radial-bots+chrome-roll@google.com
Change-Id: Ic64abf9678a79a931f6f0ff4560bb3f196020d24
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2583072Reviewed-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@{#835388}

DEPS

@@ -322,7 +322,7 @@ 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': '702723ac7599d229195aabfee0b61954ad087140',
+  'shaderc_revision': '8c2ca20216be161bfc5d79fff8d866d5fe2c0bca',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.