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

content/child/webcrypto/test/aes_kw_unittest.cc

Index: content/child/webcrypto/test/aes_kw_unittest.cc
diff --git a/content/child/webcrypto/test/aes_kw_unittest.cc b/content/child/webcrypto/test/aes_kw_unittest.cc
index 5b073d964a0da3c3ab8b4b8b809cc49b703c2a9b..559aa6b03649649eb88124b61afec3095213063d 100644
--- a/content/child/webcrypto/test/aes_kw_unittest.cc
+++ b/content/child/webcrypto/test/aes_kw_unittest.cc
@@ -34,6 +34,13 @@ TEST(WebCryptoAesKwTest, GenerateKeyBadLength) {
   }
 }
 
+TEST(WebCryptoAesKwTest, GenerateKeyEmptyUsage) {
+  blink::WebCryptoKey key;
+  EXPECT_EQ(Status::ErrorCreateKeyBadUsages(),
+            GenerateSecretKey(
+                CreateAesKwKeyGenAlgorithm(256), true, 0, &key));
+}
+
 TEST(WebCryptoAesKwTest, ImportKeyJwkKeyOpsWrapUnwrap) {
   blink::WebCryptoKey key;
   base::DictionaryValue dict;