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 5066d5d91d276bffcdb953d8ae412659518f18c8..d554154f37b9736cfda1d2b1b2e0675b8e8736d5 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();