Revert "Vulkan: Roll loader/validation layers SDK. (2/2)"

This reverts commit f15f9cec318b5b0042cca7f819b1df9dbd1872ee.

Reason for revert:
Causing a compile failure on the Fuchsia config, due to a path
difference. Will fix upstream and re-land, since it's breaking the
auto-roller.

https://chromium-review.googlesource.com/c/chromium/src/+/829878

FAILED: clang_x64/gen/third_party/angle/src/vulkan_support/angle/vulkan/parameter_validation.cpp 
python ../../third_party/vulkan-validation-layers/src/scripts/lvl_genvk.py -o clang_x64/gen/third_party/angle/src/vulkan_support/angle/vulkan -registry ../../third_party/vulkan-validation-layers/src/scripts/vk.xml parameter_validation.cpp -quiet
Error: Could not find vk_validation_error_messages.h
[906/1359] ACTION //third_party/angle/src/vulkan_support:vulkan_gen_object_tracker_cpp(//build/toolchain/linux:clang_x64)
FAILED: clang_x64/gen/third_party/angle/src/vulkan_support/angle/vulkan/object_tracker.cpp 
python ../../third_party/vulkan-validation-layers/src/scripts/lvl_genvk.py -o clang_x64/gen/third_party/angle/src/vulkan_support/angle/vulkan -registry ../../third_party/vulkan-validation-layers/src/scripts/vk.xml object_tracker.cpp -quiet
Error: Could not find vk_validation_error_messages.h

Original change's description:
> Vulkan: Roll loader/validation layers SDK. (2/2)
> 
> This hasn't been updated in a while, so there are many changes.
> It should also include better validation for memory barriers.
> 
> Also includes updated builds for SPIRV Tools and glslang.
> A few pull requests need to land before landing this in ANGLE.
> 
> This second step re-enables Vulkan and includes the updated build.
> 
> Includes a workaround for parameter_validation.h no longer being
> auto-generated, and the stale file clobbering the build.
> 
> Also includes a fix for an incorrect memory barrier.
> 
> Bug: angleproject:2237
> Change-Id: Iae611764870281ed6aa7b187ec0c4e44226c722a
> Reviewed-on: https://chromium-review.googlesource.com/759197
> Commit-Queue: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Frank Henigman <fjhenigman@chromium.org>

TBR=fjhenigman@chromium.org,jmadill@chromium.org,cwallez@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: angleproject:2237
Change-Id: I9bc60860668c1da773b6e2fdb83ecc20215e9125
Reviewed-on: https://chromium-review.googlesource.com/830926
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/scripts/generate_vulkan_layers_json.py b/scripts/generate_vulkan_layers_json.py
index e5fc773..0d806e3 100644
--- a/scripts/generate_vulkan_layers_json.py
+++ b/scripts/generate_vulkan_layers_json.py
@@ -29,13 +29,8 @@
         data = json.load(infile)
 
         # update the path
-        if not 'layer' in data:
-            raise Exception("Could not find a layer key in " + json_fname)
-
-        # The standard validation layer has no library path.
-        if 'library_path' in data['layer']:
-            prev_name = os.path.basename(data['layer']['library_path'])
-            data['layer']['library_path'] = prev_name
+        prev_name = os.path.basename(data['layer']['library_path'])
+        data['layer']['library_path'] = prev_name
 
         target_fname = os.path.join(target_dir, os.path.basename(json_fname))
         with open(target_fname, "w") as outfile: