[webcrypto] Check for empty key usages *after* key creation rather than before, to match the spec's…

components/webcrypto/algorithms/util.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 "components/webcrypto/algorithms/util.h"
 
 #include <openssl/aead.h>
 #include <openssl/bn.h>
 #include <openssl/digest.h>
 
@@ skipping 33 matching lines @@
   }
 
   size_t remainder_bits = length_bits % 8;
 
   // Zero any "unused bits" in the final byte.
   if (remainder_bits)
     bytes->back() &= ~((0xFF) >> remainder_bits);
 }
 
 Status CheckKeyCreationUsages(blink::WebCryptoKeyUsageMask all_possible_usages,
-                              blink::WebCryptoKeyUsageMask actual_usages,
-                              EmptyUsagePolicy empty_usage_policy) {
-  if (actual_usages == 0 &&
-      empty_usage_policy == EmptyUsagePolicy::REJECT_EMPTY) {
-    return Status::ErrorCreateKeyEmptyUsages();
-  }
-
+                              blink::WebCryptoKeyUsageMask actual_usages) {
   if (!ContainsKeyUsages(all_possible_usages, actual_usages))
     return Status::ErrorCreateKeyBadUsages();
   return Status::Success();
 }
 
 bool ContainsKeyUsages(blink::WebCryptoKeyUsageMask a,
                        blink::WebCryptoKeyUsageMask b) {
   return (a & b) == b;
 }
 
@@ skipping 46 matching lines @@
                            additional_data.byte_length());
   }
 
   if (!ok)
     return Status::OperationError();
   buffer->resize(len);
   return Status::Success();
 }
 
 }  // namespace webcrypto