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

chrome/renderer/autofill/autofill_agent.cc

Index: chrome/renderer/autofill/autofill_agent.cc
diff --git a/chrome/renderer/autofill/autofill_agent.cc b/chrome/renderer/autofill/autofill_agent.cc
index 9b55fcc8aab6b27f37f315cdeeac960b69a72246..8753cd57df1637f23b3a9e6d9b1c14d2c7e2ac7b 100644
--- a/chrome/renderer/autofill/autofill_agent.cc
+++ b/chrome/renderer/autofill/autofill_agent.cc
@@ -5,6 +5,7 @@
 #include "chrome/renderer/autofill/autofill_agent.h"
 
 #include "base/message_loop.h"
+#include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/autofill_messages.h"
 #include "chrome/common/chrome_constants.h"
@@ -100,7 +101,8 @@ void AutofillAgent::WillSubmitForm(WebFrame* frame,
           static_cast<FormManager::ExtractMask>(
               FormManager::EXTRACT_VALUE | FormManager::EXTRACT_OPTION_TEXT),
           &form_data)) {
-    Send(new AutofillHostMsg_FormSubmitted(routing_id(), form_data));
+    int64 timestamp = base::TimeTicks::Now().ToInternalValue();
+    Send(new AutofillHostMsg_FormSubmitted(routing_id(), form_data, timestamp));
   }
 }
 
@@ -201,8 +203,11 @@ void AutofillAgent::TextFieldDidChangeImpl(const WebInputElement& element) {
 
   webkit_glue::FormData form;
   webkit_glue::FormField field;
-  if (FindFormAndFieldForNode(element, &form, &field))
-    Send(new AutofillHostMsg_TextFieldDidChange(routing_id(), form, field));
+  if (FindFormAndFieldForNode(element, &form, &field)) {
+    int64 timestamp = base::TimeTicks::Now().ToInternalValue();
+    Send(new AutofillHostMsg_TextFieldDidChange(routing_id(), form, field,
+                                                timestamp));
+  }
 }
 
 void AutofillAgent::textFieldDidReceiveKeyDown(const WebInputElement& element,
@@ -309,10 +314,13 @@ void AutofillAgent::OnFormDataFilled(int query_id,
     return;
 
   switch (autofill_action_) {
-    case AUTOFILL_FILL:
+    case AUTOFILL_FILL: {
       form_manager_.FillForm(form, autofill_query_element_);
-      Send(new AutofillHostMsg_DidFillAutofillFormData(routing_id()));
+      int64 timestamp = base::TimeTicks::Now().ToInternalValue();
+      Send(new AutofillHostMsg_DidFillAutofillFormData(routing_id(),
+                                                       timestamp));
       break;
+    }
     case AUTOFILL_PREVIEW:
       form_manager_.PreviewForm(form, autofill_query_element_);
       Send(new AutofillHostMsg_DidPreviewAutofillFormData(routing_id()));