[Autofill] Add UMA timing metrics for requestAutocomplete dialog.

chrome/browser/autofill/autocheckout_manager.cc

Index: chrome/browser/autofill/autocheckout_manager.cc
diff --git a/chrome/browser/autofill/autocheckout_manager.cc b/chrome/browser/autofill/autocheckout_manager.cc
index 2a42bab1cc1af21af6fa1ecf600aa2191cb7c83d..6330ae3edcb75e166ed34271697cf9e11efb6947 100644
--- a/chrome/browser/autofill/autocheckout_manager.cc
+++ b/chrome/browser/autofill/autocheckout_manager.cc
@@ -67,6 +67,8 @@ FormData BuildAutocheckoutFormData() {
 
 }  // namespace
 
+namespace autofill {
+
 AutocheckoutManager::AutocheckoutManager(AutofillManager* autofill_manager)
     : autofill_manager_(autofill_manager),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
@@ -76,9 +78,9 @@ AutocheckoutManager::~AutocheckoutManager() {
 }
 
 void AutocheckoutManager::SetProceedElementDescriptor(
-    const autofill::WebElementDescriptor& proceed) {
+    const WebElementDescriptor& proceed) {
   // make a local copy.
-  proceed_descriptor_.reset(new autofill::WebElementDescriptor(proceed));
+  proceed_descriptor_.reset(new WebElementDescriptor(proceed));
 }
 
 void AutocheckoutManager::FillForms() {
@@ -122,7 +124,8 @@ void AutocheckoutManager::ShowAutocheckoutDialog(
       base::Bind(&AutocheckoutManager::ReturnAutocheckoutData,
                  weak_ptr_factory_.GetWeakPtr());
   autofill_manager_->ShowRequestAutocompleteDialog(
-      BuildAutocheckoutFormData(), frame_url, ssl_status, callback);
+      BuildAutocheckoutFormData(), frame_url, ssl_status,
+      DIALOG_REQUESTER_AUTOCHECKOUT, callback);
 }
 
 void AutocheckoutManager::ReturnAutocheckoutData(const FormStructure* result) {
@@ -174,3 +177,5 @@ void AutocheckoutManager::SetValue(const AutofillField& field,
   else
     profile_->FillFormField(field, 0, field_to_fill);
 }
+
+}  // namespace autofill