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

content/child/webcrypto/test/aes_gcm_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/stl_util.h"
 #include "content/child/webcrypto/algorithm_dispatch.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/status.h"
 #include "content/child/webcrypto/test/test_helpers.h"
 #include "content/child/webcrypto/webcrypto_util.h"
@@ skipping 93 matching lines @@
     LOG(WARNING) << "AES GCM not supported, skipping tests";
     return;
   }
 
   const unsigned short kKeyLen[] = {0, 127, 257};
   blink::WebCryptoKey key;
   for (size_t i = 0; i < arraysize(kKeyLen); ++i) {
     SCOPED_TRACE(i);
     EXPECT_EQ(Status::ErrorGenerateAesKeyLength(),
               GenerateSecretKey(CreateAesGcmKeyGenAlgorithm(kKeyLen[i]), true,
-                                0, &key));
+                                blink::WebCryptoKeyUsageDecrypt, &key));
   }
 }
 
+TEST(WebCryptoAesGcmTest, GenerateKeyEmptyUsage) {
+  if (!SupportsAesGcm()) {
+    LOG(WARNING) << "AES GCM not supported, skipping tests";
+    return;
+  }
+
+  blink::WebCryptoKey key;
+  EXPECT_EQ(Status::ErrorCreateKeyEmptyUsages(),
+            GenerateSecretKey(CreateAesGcmKeyGenAlgorithm(256), true, 0, &key));
+}
+
 TEST(WebCryptoAesGcmTest, ImportExportJwk) {
   // Some Linux test runners may not have a new enough version of NSS.
   if (!SupportsAesGcm()) {
     LOG(WARNING) << "AES GCM not supported, skipping tests";
     return;
   }
 
   const blink::WebCryptoAlgorithm algorithm =
       CreateAlgorithm(blink::WebCryptoAlgorithmIdAesGcm);
 
@@ skipping 100 matching lines @@
                               test_authentication_tag, &plain_text));
     }
   }
 }
 
 }  // namespace
 
 }  // namespace webcrypto
 
 }  // namespace content