Add served cert chain to SSLInfo

net/http/http_response_info.h

Index: net/http/http_response_info.h
diff --git a/net/http/http_response_info.h b/net/http/http_response_info.h
index e6d5ba1e22f29c6eb4f633afb90a3b2cee5a3d7e..1ce64f82698bb0b43703916b47011a5f7b0f1022 100644
--- a/net/http/http_response_info.h
+++ b/net/http/http_response_info.h
@@ -139,7 +139,9 @@ class NET_EXPORT HttpResponseInfo {
   // challenge, client certificate request is not part of an HTTP response.
   scoped_refptr<SSLCertRequestInfo> cert_request_info;
 
-  // The SSL connection info (if HTTPS).
+  // The SSL connection info (if HTTPS). Note that when a response is
+  // served from cache, not every field is present. See
+  // HttpResponseInfo::InitFromPickle().
   SSLInfo ssl_info;
 
   // The parsed response headers and status line.