[Autofill] Add UMA timing metrics for requestAutocomplete dialog.

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 2acfbba86b17d563c0efb5e918d01c8bb07254db..5bb1e656ca08a707730255db8cea4c9d26717ed0 100644
--- a/chrome/browser/autofill/autofill_manager.h
+++ b/chrome/browser/autofill/autofill_manager.h
@@ -117,6 +117,7 @@ class AutofillManager : public content::WebContentsObserver,
       const FormData& form,
       const GURL& source_url,
       const content::SSLStatus& ssl_status,
+      autofill::AutocompleteDialogRequester requester,
       const base::Callback<void(const FormStructure*)>& callback);
 
   // Happens when the autocomplete dialog runs its callback when being closed.
@@ -352,7 +353,7 @@ class AutofillManager : public content::WebContentsObserver,
   AutocompleteHistoryManager autocomplete_history_manager_;
 
   // Handles autocheckout flows.
-  AutocheckoutManager autocheckout_manager_;
+  autofill::AutocheckoutManager autocheckout_manager_;
 
   // For logging UMA metrics. Overridden by metrics tests.
   scoped_ptr<const AutofillMetrics> metric_logger_;