Check that usage isn't empty when generateKey() is called

content/child/webcrypto/nss/sym_key_nss.cc

Index: content/child/webcrypto/nss/sym_key_nss.cc
diff --git a/content/child/webcrypto/nss/sym_key_nss.cc b/content/child/webcrypto/nss/sym_key_nss.cc
index 6c0425d5229f710d872618d2e5e5d5060961d254..f0d79c116da205fdcd7b8ba3a9dd93b7ce591fdf 100644
--- a/content/child/webcrypto/nss/sym_key_nss.cc
+++ b/content/child/webcrypto/nss/sym_key_nss.cc
@@ -26,6 +26,9 @@ Status GenerateSecretKeyNss(const blink::WebCryptoKeyAlgorithm& algorithm,
                             GenerateKeyResult* result) {
   DCHECK_NE(CKM_INVALID_MECHANISM, mechanism);
 
+  if (usages == 0)
+    return Status::ErrorCreateKeyEmptyUsages();
+
   crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
   if (!slot)
     return Status::OperationError();