[webcrypto] Add RSA key generation using NSS.

content/renderer/webcrypto/webcrypto_impl_openssl.cc

Index: content/renderer/webcrypto/webcrypto_impl_openssl.cc
diff --git a/content/renderer/webcrypto/webcrypto_impl_openssl.cc b/content/renderer/webcrypto/webcrypto_impl_openssl.cc
index 5881b1bba7a7ef5c333e89468ec9aea742b9f4d0..de5b2c50c976f9dc4a3e10b67d74b5b14c54e790 100644
--- a/content/renderer/webcrypto/webcrypto_impl_openssl.cc
+++ b/content/renderer/webcrypto/webcrypto_impl_openssl.cc
@@ -297,6 +297,15 @@ bool WebCryptoImpl::GenerateKeyInternal(
   return true;
 }
 
+bool WebCryptoImpl::GenerateKeyPairInternal(
+    const WebKit::WebCryptoAlgorithm& algorithm,
+    scoped_ptr<WebKit::WebCryptoKeyHandle>* public_key,
+    scoped_ptr<WebKit::WebCryptoKeyHandle>* private_key) {
+  // TODO(padolph): Placeholder for OpenSSL implementation.
+  // Issue http://crbug.com/267888.
+  return false;
+}
+
 bool WebCryptoImpl::ImportKeyInternal(
     WebKit::WebCryptoKeyFormat format,
     const unsigned char* key_data,