[webcryto] Validate key usages during key creation.

content/child/webcrypto/webcrypto_util.h

Index: content/child/webcrypto/webcrypto_util.h
diff --git a/content/child/webcrypto/webcrypto_util.h b/content/child/webcrypto/webcrypto_util.h
index 4033321c2c07979fe82929fe08505369425c2ade..f4a2a6f65287160bb63ab23869a90a5b7b00a537 100644
--- a/content/child/webcrypto/webcrypto_util.h
+++ b/content/child/webcrypto/webcrypto_util.h
@@ -71,7 +71,12 @@ bool CreateSecretKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
                               unsigned int keylen_bytes,
                               blink::WebCryptoKeyAlgorithm* key_algorithm);
 
+// Returns true if the set bits in b make up a subset of the set bits in a.
+bool ContainsKeyUsages(blink::WebCryptoKeyUsageMask a,
+                       blink::WebCryptoKeyUsageMask b);
+
 bool IsAlgorithmRsa(blink::WebCryptoAlgorithmId alg_id);
+bool IsAlgorithmAsymmetric(blink::WebCryptoAlgorithmId alg_id);
 
 }  // namespace webcrypto