[Autofill] Add UMA timing metrics for requestAutocomplete dialog.

chrome/browser/autofill/autofill_metrics.h

Index: chrome/browser/autofill/autofill_metrics.h
diff --git a/chrome/browser/autofill/autofill_metrics.h b/chrome/browser/autofill/autofill_metrics.h
index b7143ba82d7d338b2d3be1e7ec8e9e2876c21009..299af944313782282522ed24e39867b44d89b49e 100644
--- a/chrome/browser/autofill/autofill_metrics.h
+++ b/chrome/browser/autofill/autofill_metrics.h
@@ -27,6 +27,12 @@ class AutofillMetrics {
     NUM_DEVELOPER_ENGAGEMENT_METRICS
   };
 
+  // The action the user took to dismiss a dialog.
+  enum DialogDismissalAction {
+    DIALOG_ACCEPTED = 0,  // The user accepted, i.e. confirmed, the dialog.
+    DIALOG_CANCELED       // The user canceled out of the dialog.

[Dan Beam, 2013/01/31 19:47:16]

super optional nit: trailing ,

[Ilya Sherman, 2013/02/01 09:55:17]

Left it out to be consistent with the rest of the file.

[Dan Beam, 2013/02/01 17:18:08]

Why does the rest of the file hate , :P?

+  };
+
   enum InfoBarMetric {
     INFOBAR_SHOWN = 0,  // We showed an infobar, e.g. prompting to save credit
                         // card info.
@@ -158,6 +164,14 @@ class AutofillMetrics {
 
   virtual void LogAutocheckoutInfoBarMetric(InfoBarMetric metric) const;
 
+  // This should be called when the requestAutocomplete dialog is closed.
+  // |duration| should be the time elapsed between the dialog being shown and it
+  // being closed.  |dismissal_action| should indicate whether the user
+  // dismissed the dialog by submitting the form data or by cancelling.
+  virtual void LogRequestAutocompleteUiDuration(
+      const base::TimeDelta& duration,
+      DialogDismissalAction dismissal_action) const;
+
   // This should be called when a form that has been Autofilled is submitted.
   // |duration| should be the time elapsed between form load and submission.
   virtual void LogFormFillDurationFromLoadWithAutofill(