Roll src/third_party/glslang/src c40c4bc38a76..c6a4c6d3d8b5 (1 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/glslang/+log/c40c4bc38a76..c6a4c6d3d8b5

git log c40c4bc38a76..c6a4c6d3d8b5 --date=short --first-parent --format='%ad %ae %s'
2020-03-04 johnkslang@users.noreply.github.com Improve formatting.

Created with:
  gclient setdep -r src/third_party/glslang/src@c6a4c6d3d8b5

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/glslang-chromium-autoroll
Please CC radial-bots+chrome-roll@google.com,ianelliott@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,ianelliott@google.com
Change-Id: I37a984fa2e3a3232c7fa8ec0125547305642326d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2087175Reviewed-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@{#746735}

DEPS

@@ -944,7 +944,7 @@ deps = {
     Var('chromium_git') + '/codecs/libgav1.git' + '@' + 'fa1c3c4e673cf12ffa22b8fbe4a7c79314571f1b',
 
   'src/third_party/glslang/src':
-    Var('chromium_git') + '/external/github.com/KhronosGroup/glslang.git' + '@' + 'c40c4bc38a76fb597e7a5954a20313c1bd0d66c9',
+    Var('chromium_git') + '/external/github.com/KhronosGroup/glslang.git' + '@' + 'c6a4c6d3d8b5b85b93308336534adf9c1ef0ae66',
 
   'src/third_party/google_toolbox_for_mac/src': {
       'url': Var('chromium_git') + '/external/github.com/google/google-toolbox-for-mac.git' + '@' + Var('google_toolbox_for_mac_revision'),