Roll third_party/vulkan-headers/src 0e78ffd..b4b0f99 (1 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/Vulkan-Headers/+log/0e78ffd1dcfc..b4b0f994204e

git log 0e78ffd..b4b0f99 --date=short --first-parent --format='%ad %ae %s'
2020-04-06 [email protected] Update README.md with warning of pending header changes

Created with:
  gclient setdep -r third_party/vulkan-headers/src@b4b0f994204e

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/vulkan-headers-angle-autoroll
Please CC [email protected] 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

[email protected]

Bug: None
Change-Id: I7b5b7a693c6e2e4aa6750643a2fc27be933626eb
Tbr: [email protected]
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2139096
Reviewed-by: angle-autoroll <[email protected]>
Commit-Queue: angle-autoroll <[email protected]>

Author: angle-autoroll

DEPS

@@ -49,7 +49,7 @@ vars = {
   'spirv_tools_revision': '4af38c49bfeeac536b9bf9b25be2d4bbec356972',
 
   # Current revision of Khronos Vulkan-Headers.
-  'vulkan_headers_revision': '0e78ffd1dcfc3e9f14a966b9660dbc59bd967c5c',
+  'vulkan_headers_revision': 'b4b0f994204e4fd1223260856a9fb4b738ed6b4e',
 
   # Current revision of Khronos Vulkan-Loader.
   'vulkan_loader_revision': 'bb74deab0a4dc88ec0f6c808d4f9874e8629ce5e',