https://chromium.googlesource.com/external/github.com/KhronosGroup/Vulkan-ValidationLayers.git/+log/f1b11cc29c58..236f1f090429

2020-06-08 marcin.slusarz@intel.com build: detect missing SPIRV_HEADERS_INSTALL_DIR at cmake time
2020-06-08 marcin.slusarz@intel.com build: SPIRV-Tools and glsllang are 2 separate projects

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/vulkan-validation-layers-angle-autoroll
Please CC cnorthrop@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

Bug: None
Tbr: cnorthrop@google.com
Change-Id: I12cfe46fcfbb3327f02f2c9f2f9a7f122e6dc424
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2237227Reviewed-by: angle-autoroll <angle-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: angle-autoroll <angle-autoroll@skia-public.iam.gserviceaccount.com>