Refactor the interface for generating keys.

content/child/webcrypto/nss/rsa_key_nss.h

Index: content/child/webcrypto/nss/rsa_key_nss.h
diff --git a/content/child/webcrypto/nss/rsa_key_nss.h b/content/child/webcrypto/nss/rsa_key_nss.h
index b929192a5bb0142252c107fc11771cff5ac76205..aeef810427b1180088444984a085d8deb8be90ae 100644
--- a/content/child/webcrypto/nss/rsa_key_nss.h
+++ b/content/child/webcrypto/nss/rsa_key_nss.h
@@ -43,18 +43,10 @@ class RsaHashedAlgorithm : public AlgorithmImplementation {
   virtual const char* GetJwkAlgorithm(
       const blink::WebCryptoAlgorithmId hash) const = 0;
 
-  virtual Status VerifyKeyUsagesBeforeGenerateKeyPair(
-      blink::WebCryptoKeyUsageMask combined_usage_mask,
-      blink::WebCryptoKeyUsageMask* public_usage_mask,
-      blink::WebCryptoKeyUsageMask* private_usage_mask) const OVERRIDE;
-
-  virtual Status GenerateKeyPair(
-      const blink::WebCryptoAlgorithm& algorithm,
-      bool extractable,
-      blink::WebCryptoKeyUsageMask public_usage_mask,
-      blink::WebCryptoKeyUsageMask private_usage_mask,
-      blink::WebCryptoKey* public_key,
-      blink::WebCryptoKey* private_key) const OVERRIDE;
+  virtual Status GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
+                             bool extractable,
+                             blink::WebCryptoKeyUsageMask usage_mask,
+                             GenerateKeyResult* result) const OVERRIDE;
 
   virtual Status VerifyKeyUsagesBeforeImportKey(
       blink::WebCryptoKeyFormat format,