[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 b1f14dcf0d2ba97ce1663e546f324a4f9a1efebe..c7c7724d63e065903c2dd7900484b860f5f98727 100644
--- a/content/renderer/webcrypto/webcrypto_impl_openssl.cc
+++ b/content/renderer/webcrypto/webcrypto_impl_openssl.cc
@@ -234,6 +234,15 @@ bool WebCryptoImpl::GenerateKeyInternal(
   return false;
 }
 
+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,