Enable Vulkan validation layers

BUG=dawn:150

Change-Id: Ie1b252f7fecb323badb40a226e185390d0c241e4
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/7281
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Hao Li <hao.x.li@intel.com>
diff --git a/src/dawn_native/vulkan/BackendVk.cpp b/src/dawn_native/vulkan/BackendVk.cpp
index ecd263f..6ca0a26 100644
--- a/src/dawn_native/vulkan/BackendVk.cpp
+++ b/src/dawn_native/vulkan/BackendVk.cpp
@@ -120,16 +120,18 @@
             usedKnobs.renderDocCapture = true;
         }
 #endif
-#if defined(DAWN_ENABLE_ASSERTS)
-        if (mGlobalInfo.standardValidation) {
-            layersToRequest.push_back(kLayerNameLunargStandardValidation);
-            usedKnobs.standardValidation = true;
+
+        if (GetInstance()->IsBackendValidationEnabled()) {
+            if (mGlobalInfo.standardValidation) {
+                layersToRequest.push_back(kLayerNameLunargStandardValidation);
+                usedKnobs.standardValidation = true;
+            }
+            if (mGlobalInfo.debugReport) {
+                extensionsToRequest.push_back(kExtensionNameExtDebugReport);
+                usedKnobs.debugReport = true;
+            }
         }
-        if (mGlobalInfo.debugReport) {
-            extensionsToRequest.push_back(kExtensionNameExtDebugReport);
-            usedKnobs.debugReport = true;
-        }
-#endif
+
         // Always request all extensions used to create VkSurfaceKHR objects so that they are
         // always available for embedders looking to create VkSurfaceKHR on our VkInstance.
         if (mGlobalInfo.macosSurface) {