[WebCrypto] Throw syntaxError if keyUsage is empty in ImportKey

content/child/webcrypto/nss/aes_key_nss.cc

Index: content/child/webcrypto/nss/aes_key_nss.cc
diff --git a/content/child/webcrypto/nss/aes_key_nss.cc b/content/child/webcrypto/nss/aes_key_nss.cc
index d6a7fd9cb514026bfdd5ae6fbc95daee87ca3ac4..b260b0e1eb524cfd1627f478016cca38800377e3 100644
--- a/content/child/webcrypto/nss/aes_key_nss.cc
+++ b/content/child/webcrypto/nss/aes_key_nss.cc
@@ -42,7 +42,7 @@ Status AesAlgorithm::GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
                                  bool extractable,
                                  blink::WebCryptoKeyUsageMask usages,
                                  GenerateKeyResult* result) const {
-  Status status = CheckKeyCreationUsages(all_key_usages_, usages);
+  Status status = CheckKeyCreationUsages(all_key_usages_, usages, false);

[eroman, 2014/12/09 21:04:46]

This may as well just pass true, and then remove the check in
GenerateSecretKeyNss/GenerateSecretKeyOpenssl

[Habib Virji, 2014/12/15 18:48:55]

Done.

   if (status.IsError())
     return status;
 
@@ -62,7 +62,7 @@ Status AesAlgorithm::VerifyKeyUsagesBeforeImportKey(
   switch (format) {
     case blink::WebCryptoKeyFormatRaw:
     case blink::WebCryptoKeyFormatJwk:
-      return CheckKeyCreationUsages(all_key_usages_, usages);
+      return CheckKeyCreationUsages(all_key_usages_, usages, true);
     default:
       return Status::ErrorUnsupportedImportKeyFormat();
   }