Provides a certificate for SSL client authentication on NSS sockets....

chrome/browser/renderer_host/resource_dispatcher_host.cc

Index: chrome/browser/renderer_host/resource_dispatcher_host.cc
===================================================================
--- chrome/browser/renderer_host/resource_dispatcher_host.cc	(revision 29069)
+++ chrome/browser/renderer_host/resource_dispatcher_host.cc	(working copy)
@@ -1052,6 +1052,14 @@
     net::SSLCertRequestInfo* cert_request_info) {
   DCHECK(request);
 
+#if defined(OS_LINUX)
+  bool select_first_cert = CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kAutoSSLClientAuth);
+  net::X509Certificate* cert =
+      select_first_cert && !cert_request_info->client_certs.empty() ?
+      cert_request_info->client_certs[0] : NULL;
+  request->ContinueWithCertificate(cert);
+#else
   if (cert_request_info->client_certs.empty()) {
     // No need to query the user if there are no certs to choose from.
     request->ContinueWithCertificate(NULL);
@@ -1064,6 +1072,7 @@
   info->set_ssl_client_auth_handler(
       new SSLClientAuthHandler(request, cert_request_info, io_loop_, ui_loop_));
   info->ssl_client_auth_handler()->SelectCertificate();
+#endif
 }
 
 void ResourceDispatcherHost::OnSSLCertificateError(