[Autofill] Implement Impression metric for signin promo in CC dropdown.

components/autofill/core/browser/autofill_external_delegate_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <memory>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/histogram_tester.h"
+#include "base/test/user_action_tester.h"
 #include "build/build_config.h"
 #include "components/autofill/core/browser/autofill_manager.h"
 #include "components/autofill/core/browser/autofill_metrics.h"
 #include "components/autofill/core/browser/popup_item_ids.h"
 #include "components/autofill/core/browser/suggestion_test_helpers.h"
 #include "components/autofill/core/browser/test_autofill_client.h"
 #include "components/autofill/core/browser/test_autofill_driver.h"
 #include "components/autofill/core/browser/test_autofill_external_delegate.h"
 #include "components/autofill/core/common/autofill_switches.h"
 #include "components/autofill/core/common/form_data.h"
@@ skipping 184 matching lines @@
 #endif
       static_cast<int>(POPUP_ITEM_ID_AUTOFILL_OPTIONS),
 #if !defined(OS_ANDROID)
       static_cast<int>(POPUP_ITEM_ID_SEPARATOR),
 #endif
       static_cast<int>(POPUP_ITEM_ID_CREDIT_CARD_SIGNIN_PROMO));
 
   EXPECT_CALL(autofill_client_,
               ShowAutofillPopup(_, _, SuggestionVectorIdsAre(element_ids), _));
 
+  base::UserActionTester user_action_tester;
+
   // This should call ShowAutofillPopup.
   std::vector<Suggestion> autofill_item;
   autofill_item.push_back(Suggestion());
   autofill_item[0].frontend_id = kAutofillProfileId;
   external_delegate_->OnSuggestionsReturned(kQueryId, autofill_item);
+  EXPECT_EQ(1, user_action_tester.GetActionCount(
+                   "Signin_Impression_FromAutofillDropdown"));
 
   EXPECT_CALL(
       *autofill_manager_,
       FillOrPreviewForm(AutofillDriver::FORM_DATA_ACTION_FILL, _, _, _, _));
   EXPECT_CALL(autofill_client_, HideAutofillPopup());
 
   // This should trigger a call to hide the popup since we've selected an
   // option.
   external_delegate_->DidAcceptSuggestion(autofill_item[0].value,
                                           autofill_item[0].frontend_id, 0);
@@ skipping 425 matching lines @@
               RendererShouldFillFieldWithValue(dummy_string));
   base::HistogramTester histogram_tester;
   external_delegate_->DidAcceptSuggestion(dummy_string,
                                           POPUP_ITEM_ID_AUTOCOMPLETE_ENTRY,
                                           0);
   histogram_tester.ExpectUniqueSample(
       "Autofill.SuggestionAcceptedIndex.Autocomplete", 0, 1);
 }
 
 }  // namespace autofill