Roll third_party/shaderc/ a10a0b334..ced9c72d0 (2 commits)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/a10a0b33493e..ced9c72d005e

$ git log a10a0b334..ced9c72d0 --date=short --no-merges --format='%ad %ae %s'
2020-04-20 rharrison Add support for options.hlsl.nonwritable_uav_texture_as_srv (#1048)
2020-04-20 rharrison Rolling 6 dependencies and update expectations (#1047)

Created with:
  roll-dep third_party/shaderc

Change-Id: I1a1f22266c9efcb941c55d96e5611708e28500ab
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/20100
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/DEPS b/DEPS
index 4de6de6..67890ed 100644
--- a/DEPS
+++ b/DEPS
@@ -79,7 +79,7 @@
     'condition': 'dawn_standalone',
   },
   'third_party/shaderc': {
-    'url': '{chromium_git}/external/github.com/google/shaderc@a10a0b33493e3ff1c0de1dc8406ed8de230ba8c1',
+    'url': '{chromium_git}/external/github.com/google/shaderc@ced9c72d005e3002a24683e1b94b7fb978b10144',
     'condition': 'dawn_standalone',
   },