Refactor: Extract common code for generating asymmetric keys to a helper.

content/child/webcrypto/webcrypto_util.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_WEBCRYPTO_UTIL_H_
 #define CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 
 #include <stdint.h>
 #include <string>
 
@@ skipping 112 matching lines @@
 // The "get key length" operation for AES keys.
 Status GetAesKeyLength(const blink::WebCryptoAlgorithm& key_length_algorithm,
                        bool* has_length_bits,
                        unsigned int* length_bits);
 
 // The "get key length" operation for HMAC keys.
 Status GetHmacKeyLength(const blink::WebCryptoAlgorithm& key_length_algorithm,
                         bool* has_length_bits,
                         unsigned int* length_bits);
 
+// Splits the combined usages given to GenerateKey() into the respective usages
+// for the public key and private key. Returns an error if the usages are
+// invalid.
+Status GetUsagesForGenerateAsymmetricKey(
+    blink::WebCryptoKeyUsageMask combined_usages,
+    blink::WebCryptoKeyUsageMask all_public_usages,
+    blink::WebCryptoKeyUsageMask all_private_usages,
+    blink::WebCryptoKeyUsageMask* public_usages,
+    blink::WebCryptoKeyUsageMask* private_usages);
+
 }  // namespace webcrypto
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_