Roll third_party/vulkan-validation-layers/src f34b9fb086b3..a749c31b749b (3 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/Vulkan-ValidationLayers.git/+log/f34b9fb086b3..a749c31b749b

git log f34b9fb086b3..a749c31b749b --date=short --first-parent --format='%ad %ae %s'
2019-12-10 tony@lunarg.com tests: Add pos test for GetProcAddr with extensions
2019-12-10 tony@lunarg.com layers: Fix GetProcAddr for promoted extensions
2019-12-09 shannon@lunarg.com build: Update known-good for 1.1.129 Vulkan header

Created with:
  gclient setdep -r third_party/vulkan-validation-layers/src@a749c31b749b

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 ianelliot@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: ianelliot@google.com
Change-Id: I34b27bb71b6806f20019976863dd7760c9fed0cd
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1959774
Reviewed-by: angle-autoroll <angle-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: angle-autoroll <angle-autoroll@skia-public.iam.gserviceaccount.com>

Author: angle-autoroll

DEPS

@@ -60,7 +60,7 @@ vars = {
   'vulkan_tools_revision': '5ceb7be9a3bf86f34ade5a7f72459248d99a4b76',
 
   # Current revision of Khronos Vulkan-ValidationLayers.
-  'vulkan_validation_revision': 'f34b9fb086b33d1bbc8d5262eb1fb2e86514f6dd',
+  'vulkan_validation_revision': 'a749c31b749b652ca3a476bda463c6a4e1d7c7e1',
 
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling catapult