Roll src/third_party/shaderc/src 4399459c1920..82a9846c4377 (1 commits)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/4399459c1920..82a9846c4377

git log 4399459c1920..82a9846c4377 --date=short --first-parent --format='%ad %ae %s'
2019-12-18 rharrison@google.com Adding in missing APIs for MSL support in Dawn (#943)

Created with:
  gclient setdep -r src/third_party/shaderc/src@82a9846c4377

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: I9882c1813526c43e80b609ef7c95512cdf60c975
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1973939Reviewed-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@{#725985}

DEPS

@@ -302,7 +302,7 @@ 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': '4399459c192085e44270b3dea25c0d3224ad77df',
+  'shaderc_revision': '82a9846c4377773dea03fde16ae4271ba9ddd8c1',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.