[Offline Pages] Adds duplicate detection metrics.

components/offline_pages/offline_page_model_impl_unittest.cc

 // Copyright 2015 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/offline_pages/offline_page_model_impl.h"
 
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
+#include "base/metrics/statistics_recorder.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/histogram_tester.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/test_mock_time_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/offline_pages/client_namespace_constants.h"
@@ skipping 1007 matching lines @@
   EXPECT_EQ(1UL, ids.size());
 
   std::set<int64_t> id_set;
   for (size_t i = 0; i < ids.size(); i++) {
     id_set.insert(ids[i]);
   }
 
   EXPECT_TRUE(id_set.find(offline2) != id_set.end());
 }
 
+TEST_F(OfflinePageModelImplTest, DownloadMetrics) {
+  EXPECT_FALSE(HasPages(kUserRequestedNamespace));
+  SavePage(kTestUrl, kTestUserRequestedClientId);
+  histograms().ExpectUniqueSample(
+      "OfflinePages.DownloadSavedPageDuplicateCount", 1, 1);
+  FastForwardBy(base::TimeDelta::FromMinutes(1));
+  histograms().ExpectTotalCount(
+      "OfflinePages.DownloadSavedPageTimeSinceDuplicateSaved", 0);
+  SavePage(kTestUrl, kTestUserRequestedClientId);
+  histograms().ExpectTotalCount("OfflinePages.DownloadSavedPageDuplicateCount",
+                                2);
+  histograms().ExpectBucketCount("OfflinePages.DownloadSavedPageDuplicateCount",
+                                 2, 1);
+  histograms().ExpectBucketCount("OfflinePages.DownloadSavedPageDuplicateCount",
+                                 1, 1);
+  histograms().ExpectTotalCount(
+      "OfflinePages.DownloadSavedPageTimeSinceDuplicateSaved", 1);
+  histograms().ExpectTotalCount(
+      "OfflinePages.DownloadDeletedPageDuplicateCount", 0);
+
+  // void DeletePage(int64_t offline_id, const DeletePageCallback& callback) {
+  const std::vector<int64_t> ids =
+      GetOfflineIdsForClientId(kTestUserRequestedClientId);
+  ASSERT_EQ(2U, ids.size());
+
+  DeletePage(ids[0], base::Bind(&OfflinePageModelImplTest::OnDeletePageDone,
+                                AsWeakPtr()));
+  PumpLoop();
+  histograms().ExpectUniqueSample(
+      "OfflinePages.DownloadDeletedPageDuplicateCount", 2, 1);
+  DeletePage(ids[1], base::Bind(&OfflinePageModelImplTest::OnDeletePageDone,
+                                AsWeakPtr()));
+  PumpLoop();
+  // No change when we delete the last page.
+  histograms().ExpectTotalCount(
+      "OfflinePages.DownloadDeletedPageDuplicateCount", 2);
+  histograms().ExpectBucketCount(
+      "OfflinePages.DownloadDeletedPageDuplicateCount", 1, 1);
+  histograms().ExpectBucketCount(
+      "OfflinePages.DownloadDeletedPageDuplicateCount", 2, 1);
+}
+
 TEST_F(OfflinePageModelImplTest, GetBestPage) {
   // We will save 3 pages - two for the same URL, and one for a different URL.
   // Correct behavior will pick the most recently saved page for the correct
   // URL.
   std::pair<SavePageResult, int64_t> saved_pages[3];
   saved_pages[0] = SavePage(kTestUrl, kTestClientId1);
   saved_pages[1] = SavePage(kTestUrl, kTestClientId1);
   saved_pages[2] = SavePage(kTestUrl2, kTestClientId2);
 
   for (const auto& save_result : saved_pages) {
@@ skipping 134 matching lines @@
   // Check if feature is correctly enabled by command-line flag.
   scoped_feature_list.reset(new base::test::ScopedFeatureList);
   scoped_feature_list->InitFromCommandLine(
       std::string(kOfflineBookmarksFeature.name) + "," +
           kOfflinePagesSharingFeature.name,
       "");
   EXPECT_TRUE(offline_pages::IsOfflinePagesSharingEnabled());
 }
 
 }  // namespace offline_pages