Roll shaderc from 6216d098d8ab to 1520e40f5e2b (1 revision)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/6216d098d8ab..1520e40f5e2b

2020-12-03 dneto@google.com copyright check: Exclude .venv in source tree

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: Ief57990d01d5fa03b9a494d76b36da7f2d4ef1dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2570014Reviewed-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@{#833148}

DEPS

@@ -326,7 +326,7 @@ 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': '6216d098d8abe3ccda8781016c4f69372c48afb9',
+  'shaderc_revision': '1520e40f5e2b6d480f06a467406dade164195bf9',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.