Add logging for submitted Autofill field types.

chrome/browser/autofill/form_structure.cc

Index: chrome/browser/autofill/form_structure.cc
diff --git a/chrome/browser/autofill/form_structure.cc b/chrome/browser/autofill/form_structure.cc
index 407ac8dd6dda975ac6844124152d459674e8e9c0..883c5d494e0c493e4735ac185ef87c86254c1fa5 100644
--- a/chrome/browser/autofill/form_structure.cc
+++ b/chrome/browser/autofill/form_structure.cc
@@ -355,6 +355,9 @@ bool FormStructure::EncodeUploadRequest(
   *encoded_xml = kXMLDeclaration;
   *encoded_xml += autofill_request_xml.Str().c_str();
 
+  // To enable this logging, run with the flag --vmodule="form_structure=2".
+  VLOG(2) << "\n" << *encoded_xml;
+
   return true;
 }