[Autofill] Add UMA timing metrics for requestAutocomplete dialog.

chrome/browser/ui/autofill/autofill_dialog_view.h

Index: chrome/browser/ui/autofill/autofill_dialog_view.h
diff --git a/chrome/browser/ui/autofill/autofill_dialog_view.h b/chrome/browser/ui/autofill/autofill_dialog_view.h
index 32738307de94b6318b17394bb70c9ba4cd218598..a572e30756d7bc10c57b83c0f3a4fdabc3d89db7 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_view.h
+++ b/chrome/browser/ui/autofill/autofill_dialog_view.h
@@ -55,6 +55,12 @@ class AutofillDialogView {
   // be in [0.0, 1.0].
   virtual void UpdateProgressBar(double value) = 0;
 
+  // Simulates the user pressing 'Submit' to accept the dialog.
+  virtual void SubmitForTesting() = 0;
+
+  // Simulates the user pressing 'Cancel' to abort the dialog.
+  virtual void CancelForTesting() = 0;
+
   // Factory function to create the dialog (implemented once per view
   // implementation). |controller| will own the created dialog.
   static AutofillDialogView* Create(AutofillDialogController* controller);