[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..7ceadbefcf8acc5d410ff11cfb110df143e3f07e 100644
--- a/chrome/browser/autofill/autofill_metrics.h
+++ b/chrome/browser/autofill/autofill_metrics.h
@@ -9,6 +9,7 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "chrome/browser/autofill/autofill_manager_delegate.h"
 #include "chrome/browser/autofill/field_types.h"
 
 namespace base {
@@ -27,6 +28,12 @@ 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.
+  };
+
   enum InfoBarMetric {
     INFOBAR_SHOWN = 0,  // We showed an infobar, e.g. prompting to save credit
                         // card info.
@@ -158,6 +165,16 @@ class AutofillMetrics {
 
   virtual void LogAutocheckoutInfoBarMetric(InfoBarMetric metric) const;
 
+  // This should be called when the requestAutocomplete dialog, invoked by the
+  // |requester|, 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,
+      autofill::DialogRequester requester,
+      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(