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

chrome/browser/autofill/autofill_manager.h

Index: chrome/browser/autofill/autofill_manager.h
diff --git a/chrome/browser/autofill/autofill_manager.h b/chrome/browser/autofill/autofill_manager.h
index d488a30acb6d0523fae1b1506e689763cb74908c..42186828b64f31801bc74fcde7a9969449a8d0eb 100644
--- a/chrome/browser/autofill/autofill_manager.h
+++ b/chrome/browser/autofill/autofill_manager.h
@@ -17,6 +17,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/string16.h"
+#include "base/time.h"
 #include "chrome/browser/autofill/autofill_download.h"
 #include "chrome/browser/autofill/field_types.h"
 #include "chrome/browser/autofill/form_structure.h"
@@ -113,10 +114,12 @@ class AutofillManager : public TabContentsObserver,
   void UnpackGUIDs(int id, GUIDPair* cc_guid, GUIDPair* profile_guid);
 
  private:
-  void OnFormSubmitted(const webkit_glue::FormData& form);
+  void OnFormSubmitted(const webkit_glue::FormData& form,
+                       int64 timestamp);

[jar (doing other things), 2011/08/31 17:02:21]

The name timestamp is is not defined.  You should at a minimimum have a comment
indicating what this argument is.  After reading a lot of this CL, I concluded
that it is probably the internal representation of a TimeTicks().   If possible,
it would be much nicer to consistently use TimeTicks(), and only serialize when
absolutely necessary, rather than defining interfaces which pass around the
internal value as some integral type.

It also was not clear why you needed to augment the time.h class to deserialize
TimeDelta values.  Is that being done in this CL somewhere?

[Ilya Sherman, 2011/08/31 21:56:23]

The timestamp is being serialized for IPC communication, but you're right that
there's a better place to do that serialization.  Done.
It's being used to set mock expectations in the unit tests.  I've also updated
the IPC serialization code to use this.

   void OnFormsSeen(const std::vector<webkit_glue::FormData>& forms);
   void OnTextFieldDidChange(const webkit_glue::FormData& form,
-                            const webkit_glue::FormField& field);
+                            const webkit_glue::FormField& field,
+                            uint64 timestamp);
   void OnQueryFormFieldAutofill(int query_id,
                                 const webkit_glue::FormData& form,
                                 const webkit_glue::FormField& field);
@@ -126,7 +129,7 @@ class AutofillManager : public TabContentsObserver,
                               int unique_id);
   void OnShowAutofillDialog();
   void OnDidPreviewAutofillFormData();
-  void OnDidFillAutofillFormData();
+  void OnDidFillAutofillFormData(uint64 timestamp);
   void OnDidShowAutofillSuggestions(bool is_new_popup);
 
   // Fills |host| with the RenderViewHost for this tab.
@@ -233,6 +236,9 @@ class AutofillManager : public TabContentsObserver,
   bool user_did_autofill_;
   // Has the user edited a field that was previously autofilled?
   bool user_did_edit_autofilled_field_;
+  // When the user first interacted with a potentially fillable form on this
+  // page.
+  base::TimeTicks initial_interaction_timestamp_;
 
   // Our copy of the form data.
   ScopedVector<FormStructure> form_structures_;
@@ -277,6 +283,7 @@ class AutofillManager : public TabContentsObserver,
   FRIEND_TEST_ALL_PREFIXES(AutofillMetricsTest,
                            UserHappinessFormLoadAndSubmission);
   FRIEND_TEST_ALL_PREFIXES(AutofillMetricsTest, UserHappinessFormInteraction);
+  FRIEND_TEST_ALL_PREFIXES(AutofillMetricsTest, FormFillDuration);
 
   DISALLOW_COPY_AND_ASSIGN(AutofillManager);
 };