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

components/webcrypto/algorithms/util.h

Index: components/webcrypto/algorithms/util.h
diff --git a/components/webcrypto/algorithms/util.h b/components/webcrypto/algorithms/util.h
index 2132683412c365fb66f8384cbc2cc09c4dc782a0..62bb22dec35bd132f6fcecef7ae5ba60f8656fab 100644
--- a/components/webcrypto/algorithms/util.h
+++ b/components/webcrypto/algorithms/util.h
@@ -52,19 +52,10 @@ T NumBitsToBytes(T x) {
   return (x / 8) + (7 + (x % 8)) / 8;
 }
 
-enum class EmptyUsagePolicy {
-  // Allow keys to have empty usages.
-  ALLOW_EMPTY,
-
-  // Do not allow keys to have empty usages.
-  REJECT_EMPTY,
-};
-
 // Verifies whether a key can be created using |actual_usages| when the
 // algorithm supports |all_possible_usages|.
 Status CheckKeyCreationUsages(blink::WebCryptoKeyUsageMask all_possible_usages,
-                              blink::WebCryptoKeyUsageMask actual_usages,
-                              EmptyUsagePolicy empty_usage_policy);
+                              blink::WebCryptoKeyUsageMask actual_usages);
 
 // TODO(eroman): This doesn't really belong in this file. Move it into Blink
 // instead.