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

components/webcrypto/algorithms/secret_key_util.h

Index: components/webcrypto/algorithms/secret_key_util.h
diff --git a/components/webcrypto/algorithms/secret_key_util.h b/components/webcrypto/algorithms/secret_key_util.h
index 5a0adfb60299ade2f131523d81903545d020375d..511440628d426ec932ac067d5b1ee82633e4cc13 100644
--- a/components/webcrypto/algorithms/secret_key_util.h
+++ b/components/webcrypto/algorithms/secret_key_util.h
@@ -41,11 +41,6 @@ Status CreateWebCryptoSecretKey(const CryptoData& key_data,
                                 blink::WebCryptoKeyUsageMask usages,
                                 blink::WebCryptoKey* key);
 
-// Checks that |actual_usages| is a non-empty subset of |all_possible_usages|.
-Status CheckSecretKeyCreationUsages(
-    blink::WebCryptoKeyUsageMask all_possible_usages,
-    blink::WebCryptoKeyUsageMask actual_usages);
-
 // Writes a JWK-formatted symmetric key to |jwk_key_data|.
 //  * raw_key_data: The actual key data
 //  * algorithm: The JWK algorithm name (i.e. "alg")