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

content/child/webcrypto/status.h

 // 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.
 
 #ifndef CONTENT_CHILD_WEBCRYPTO_STATUS_H_
 #define CONTENT_CHILD_WEBCRYPTO_STATUS_H_
 
 #include <string>
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebCrypto.h"
@@ skipping 196 matching lines @@
 
   // The key length specified when generating a key was invalid. Either it was
   // zero, or it was not a multiple of 8 bits.
   static Status ErrorGenerateKeyLength();
 
   // Attempted to create a key (either by importKey(), generateKey(), or
   // unwrapKey()) however the key usages were not applicable for the key type
   // and algorithm.
   static Status ErrorCreateKeyBadUsages();
 
+  // No usages were specified when creating a key.

[eroman, 2014/11/21 23:35:34]

nit: "when creating a private or secret key" (since some public keys like ECDH
can have empty usages).

[nharper, 2014/11/22 00:26:45]

Done.

+  static Status ErrorCreateKeyEmptyUsages();
+
   // An EC key imported using SPKI/PKCS8 format had the wrong curve specified in
   // the key.
   static Status ErrorImportedEcKeyIncorrectCurve();
 
   // The "crv" member for a JWK did not match the expectations from importKey()
   static Status ErrorJwkIncorrectCrv();
 
   // The EC key failed validation (coordinates don't lie on curve, out of range,
   // etc.)
   static Status ErrorEcKeyInvalid();
@@ skipping 17 matching lines @@
   Type type_;
   blink::WebCryptoErrorType error_type_;
   std::string error_details_;
 };
 
 }  // namespace webcrypto
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEBCRYPTO_STATUS_H_