Add metrics to measure time elapsed between form load and form submission with or without Autofill.

ipc/ipc_message_utils.h

Index: ipc/ipc_message_utils.h
diff --git a/ipc/ipc_message_utils.h b/ipc/ipc_message_utils.h
index e7bbe344624295b22ae0481b13e31013f32ac1f5..7c46f900053b0d339daf093c6d37717cb65c72d6 100644
--- a/ipc/ipc_message_utils.h
+++ b/ipc/ipc_message_utils.h
@@ -105,6 +105,7 @@ class DictionaryValue;
 class ListValue;
 class Time;
 class TimeDelta;
+class TimeTicks;
 struct FileDescriptor;
 }
 
@@ -332,6 +333,14 @@ struct IPC_EXPORT ParamTraits<base::TimeDelta> {
   static void Log(const param_type& p, std::string* l);
 };
 
+template <>
+struct IPC_EXPORT ParamTraits<base::TimeTicks> {
+  typedef base::TimeTicks param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
 #if defined(OS_WIN)
 template <>
 struct ParamTraits<LOGFONT> {