[NTP::SectionOrder] Make ClickBasedRanker move dismissed sections down.

components/ntp_snippets/content_suggestions_service_unittest.cc

 // Copyright 2016 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 "components/ntp_snippets/content_suggestions_service.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/ntp_snippets/category_info.h"
 #include "components/ntp_snippets/category_rankers/constant_category_ranker.h"
 #include "components/ntp_snippets/category_rankers/fake_category_ranker.h"
+#include "components/ntp_snippets/category_rankers/mock_category_ranker.h"
 #include "components/ntp_snippets/category_status.h"
 #include "components/ntp_snippets/content_suggestion.h"
 #include "components/ntp_snippets/content_suggestions_provider.h"
 #include "components/ntp_snippets/user_classifier.h"
 #include "components/prefs/testing_pref_service.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/image/image.h"
 
 using testing::_;
@@ skipping 705 matching lines @@
               ElementsAre(first_category, second_category));
 
   // The order to display (in the ranker) changes.
   raw_fake_ranker->SetOrder({second_category, first_category});
 
   // Categories order should reflect the new order.
   EXPECT_THAT(service()->GetCategories(),
               ElementsAre(second_category, first_category));
 }
 
+TEST_F(ContentSuggestionsServiceTest,
+       ShouldForwardDismissedCategoryToCategoryRanker) {
+  auto mock_ranker = base::MakeUnique<MockCategoryRanker>();
+  MockCategoryRanker* raw_mock_ranker = mock_ranker.get();
+  SetCategoryRanker(std::move(mock_ranker));
+
+  // The service is recreated to pick up the new ranker.
+  ResetService();
+
+  Category category = Category::FromKnownCategory(KnownCategories::BOOKMARKS);
+  MockProvider* provider = RegisterProvider(category);
+  provider->FireCategoryStatusChangedWithCurrentStatus(category);
+
+  EXPECT_CALL(*raw_mock_ranker, OnCategoryDismissed(category));
+  service()->DismissCategory(category);
+}
+
 }  // namespace ntp_snippets