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

chrome/renderer/autofill/form_autocomplete_browsertest.cc

Index: chrome/renderer/autofill/form_autocomplete_browsertest.cc
diff --git a/chrome/renderer/autofill/form_autocomplete_browsertest.cc b/chrome/renderer/autofill/form_autocomplete_browsertest.cc
index 9d58e943ff2f8bf85263d4016d85ef39c3832d32..196b30a4b172a67e677ac2d540bf8f662fedebb9 100644
--- a/chrome/renderer/autofill/form_autocomplete_browsertest.cc
+++ b/chrome/renderer/autofill/form_autocomplete_browsertest.cc
@@ -35,7 +35,7 @@ TEST_F(FormAutocompleteTest, NormalFormSubmit) {
       AutofillHostMsg_FormSubmitted::ID);
   ASSERT_TRUE(message != NULL);
 
-  Tuple1<FormData> forms;
+  Tuple2<FormData, int64> forms;  // also includes timestamp, which is ignored
   AutofillHostMsg_FormSubmitted::Read(message, &forms);
   ASSERT_EQ(2U, forms.a.fields.size());
 
@@ -83,7 +83,7 @@ TEST_F(FormAutocompleteTest, AutoCompleteOffInputSubmit) {
       AutofillHostMsg_FormSubmitted::ID);
   ASSERT_TRUE(message != NULL);
 
-  Tuple1<FormData> forms;
+  Tuple2<FormData, int64> forms;  // also includes timestamp, which is ignored
   AutofillHostMsg_FormSubmitted::Read(message, &forms);
   ASSERT_EQ(1U, forms.a.fields.size());