Tests: Allow tests to function without VVLs.

This is necessary to run angle_end2end_tests with sanitizers. We
don't currently support building the VVL in sanitized configs.

Bug: b/168744561
Change-Id: If16a25ac5786f5f5aeb8ae50d9f7fa22c6c87995
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2415513
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

src/libANGLE/renderer/vulkan/BUILD.gn

@@ -168,6 +168,9 @@ config("angle_vulkan_backend_config") {
   if (angle_enable_vulkan_gpu_trace_events) {
     defines += [ "ANGLE_ENABLE_VULKAN_GPU_TRACE_EVENTS=1" ]
   }
+  if (angle_enable_vulkan_validation_layers) {
+    defines += [ "ANGLE_ENABLE_VULKAN_VALIDATION_LAYERS" ]
+  }
 }
 
 angle_source_set("angle_vk_mem_alloc_wrapper") {

src/tests/test_utils/ANGLETest.cpp

@@ -365,10 +365,13 @@ ANGLETestBase::ANGLETestBase(const PlatformParameters &params)
     PlatformParameters withMethods            = params;
     withMethods.eglParameters.platformMethods = &gDefaultPlatformMethods;
 
-    // We don't build vulkan debug layers on Mac (http://anglebug.com/4376)
-    if (IsOSX() && withMethods.getRenderer() == EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE)
+    if (withMethods.getRenderer() == EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE)
     {
+#if defined(ANGLE_ENABLE_VULKAN_VALIDATION_LAYERS)
+        withMethods.eglParameters.debugLayersEnabled = true;
+#else
         withMethods.eglParameters.debugLayersEnabled = false;
+#endif
     }
 
     auto iter = gFixtures.find(withMethods);