[Part-2]Add Statistics for SupervisedUserSettingService during merging and syncing data.

chrome/browser/supervised_user/supervised_user_settings_service_unittest.cc

 // Copyright 2014 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 "chrome/browser/supervised_user/supervised_user_settings_service.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 52 matching lines @@
  protected:
   SupervisedUserSettingsServiceTest() : settings_service_(nullptr) {}
   ~SupervisedUserSettingsServiceTest() override {}
 
   scoped_ptr<syncer::SyncChangeProcessor> CreateSyncProcessor() {
     sync_processor_.reset(new syncer::FakeSyncChangeProcessor);
     return scoped_ptr<syncer::SyncChangeProcessor>(
         new syncer::SyncChangeProcessorWrapperForTest(sync_processor_.get()));
   }
 
-  void StartSyncing(const syncer::SyncDataList& initial_sync_data) {
+  syncer::SyncMergeResult StartSyncing(
+      const syncer::SyncDataList& initial_sync_data) {
     scoped_ptr<syncer::SyncErrorFactory> error_handler(
         new MockSyncErrorFactory(syncer::SUPERVISED_USER_SETTINGS));
     syncer::SyncMergeResult result = settings_service_.MergeDataAndStartSyncing(
         syncer::SUPERVISED_USER_SETTINGS, initial_sync_data,
         CreateSyncProcessor(), std::move(error_handler));
     EXPECT_FALSE(result.error().IsSet());
+    return result;
   }
 
   void UploadSplitItem(const std::string& key, const std::string& value) {
     split_items_.SetStringWithoutPathExpansion(key, value);
     settings_service_.UploadItem(
         SupervisedUserSettingsService::MakeSplitSettingKey(kSplitItemName,
                                                            key),
         scoped_ptr<base::Value>(new base::StringValue(value)));
   }
 
   void UploadAtomicItem(const std::string& value) {
     atomic_setting_value_.reset(new base::StringValue(value));
     settings_service_.UploadItem(
         kAtomicItemName,
         scoped_ptr<base::Value>(new base::StringValue(value)));
   }
 
   void VerifySyncDataItem(syncer::SyncData sync_data) {
     const sync_pb::ManagedUserSettingSpecifics& supervised_user_setting =
         sync_data.GetSpecifics().managed_user_setting();
-    base::Value* expected_value = NULL;
+    base::Value* expected_value = nullptr;
     if (supervised_user_setting.name() == kAtomicItemName) {
       expected_value = atomic_setting_value_.get();
     } else {
       EXPECT_TRUE(base::StartsWith(supervised_user_setting.name(),
                                    std::string(kSplitItemName) + ':',
                                    base::CompareCase::SENSITIVE));
       std::string key =
           supervised_user_setting.name().substr(strlen(kSplitItemName) + 1);
       EXPECT_TRUE(split_items_.GetWithoutPathExpansion(key, &expected_value));
     }
@@ skipping 32 matching lines @@
   scoped_ptr<base::DictionaryValue> settings_;
   scoped_ptr<base::CallbackList<void(
       const base::DictionaryValue*)>::Subscription> user_settings_subscription_;
 
   scoped_ptr<syncer::FakeSyncChangeProcessor> sync_processor_;
 };
 
 TEST_F(SupervisedUserSettingsServiceTest, ProcessAtomicSetting) {
   StartSyncing(syncer::SyncDataList());
   ASSERT_TRUE(settings_);
-  const base::Value* value = NULL;
+  const base::Value* value = nullptr;
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
 
   settings_.reset();
   syncer::SyncData data =
       SupervisedUserSettingsService::CreateSyncDataForSetting(
           kSettingsName, base::StringValue(kSettingsValue));
   syncer::SyncChangeList change_list;
   change_list.push_back(
       syncer::SyncChange(FROM_HERE, syncer::SyncChange::ACTION_ADD, data));
   syncer::SyncError error =
       settings_service_.ProcessSyncChanges(FROM_HERE, change_list);
   EXPECT_FALSE(error.IsSet()) << error.ToString();
   ASSERT_TRUE(settings_);
   ASSERT_TRUE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
   std::string string_value;
   EXPECT_TRUE(value->GetAsString(&string_value));
   EXPECT_EQ(kSettingsValue, string_value);
 }
 
 TEST_F(SupervisedUserSettingsServiceTest, ProcessSplitSetting) {
   StartSyncing(syncer::SyncDataList());
   ASSERT_TRUE(settings_);
-  const base::Value* value = NULL;
+  const base::Value* value = nullptr;
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
 
   base::DictionaryValue dict;
   dict.SetString("foo", "bar");
   dict.SetBoolean("awesomesauce", true);
   dict.SetInteger("eaudecologne", 4711);
 
   settings_.reset();
   syncer::SyncChangeList change_list;
   for (base::DictionaryValue::Iterator it(dict); !it.IsAtEnd(); it.Advance()) {
     syncer::SyncData data =
         SupervisedUserSettingsService::CreateSyncDataForSetting(
             SupervisedUserSettingsService::MakeSplitSettingKey(kSettingsName,
                                                                it.key()),
             it.value());
     change_list.push_back(
         syncer::SyncChange(FROM_HERE, syncer::SyncChange::ACTION_ADD, data));
   }
   syncer::SyncError error =
       settings_service_.ProcessSyncChanges(FROM_HERE, change_list);
   EXPECT_FALSE(error.IsSet()) << error.ToString();
   ASSERT_TRUE(settings_);
   ASSERT_TRUE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
-  const base::DictionaryValue* dict_value = NULL;
+  const base::DictionaryValue* dict_value = nullptr;
   ASSERT_TRUE(value->GetAsDictionary(&dict_value));
   EXPECT_TRUE(dict_value->Equals(&dict));
 }
 
+TEST_F(SupervisedUserSettingsServiceTest, Merge) {
+  syncer::SyncMergeResult result = StartSyncing(syncer::SyncDataList());
+  EXPECT_EQ(0, result.num_items_added());
+  EXPECT_EQ(0, result.num_items_deleted());
+  EXPECT_EQ(0, result.num_items_modified());
+  EXPECT_EQ(0, result.num_items_before_association());
+  EXPECT_EQ(0, result.num_items_after_association());
+
+  ASSERT_TRUE(settings_);
+  const base::Value* value = nullptr;
+  EXPECT_FALSE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
+
+  base::DictionaryValue dict;
+  dict.SetString("foo", "bar");
+  dict.SetBoolean("awesomesauce", true);
+  dict.SetInteger("eaudecologne", 4711);
+
+  settings_.reset();
+  syncer::SyncDataList sync_data;
+  sync_data.push_back(SupervisedUserSettingsService::CreateSyncDataForSetting(
+      kSettingsName, base::StringValue(kSettingsValue)));
+  for (base::DictionaryValue::Iterator it(dict); !it.IsAtEnd(); it.Advance()) {
+    sync_data.push_back(SupervisedUserSettingsService::CreateSyncDataForSetting(
+        SupervisedUserSettingsService::MakeSplitSettingKey(kSettingsName,
+                                                           it.key()),
+        it.value()));
+  }
+
+  result = StartSyncing(sync_data);
+  EXPECT_EQ(4, result.num_items_added());
+  EXPECT_EQ(0, result.num_items_deleted());
+  EXPECT_EQ(0, result.num_items_modified());
+  EXPECT_EQ(0, result.num_items_before_association());
+  EXPECT_EQ(4, result.num_items_after_association());
+
+  settings_service_.StopSyncing(syncer::SUPERVISED_USER_SETTINGS);
+  sync_data.clear();
+  // Adding split Item in the queue.
+  UploadSplitItem("blurp", "baz");
+  // Adding atomic Item in the queue.
+  UploadAtomicItem("hurdle");
+
+  dict.Clear();
+  dict.SetString("foo", "burp");
+  dict.SetString("item", "first");
+
+  for (base::DictionaryValue::Iterator it(dict); !it.IsAtEnd(); it.Advance()) {
+    sync_data.push_back(SupervisedUserSettingsService::CreateSyncDataForSetting(
+        SupervisedUserSettingsService::MakeSplitSettingKey(kSettingsName,
+                                                           it.key()),
+        it.value()));
+  }
+
+  result = StartSyncing(sync_data);
+  EXPECT_EQ(3, result.num_items_added());
+  EXPECT_EQ(3, result.num_items_deleted());
+  EXPECT_EQ(1, result.num_items_modified());
+  EXPECT_EQ(4, result.num_items_before_association());
+  EXPECT_EQ(4, result.num_items_after_association());
+}
+
 TEST_F(SupervisedUserSettingsServiceTest, SetLocalSetting) {
-  const base::Value* value = NULL;
+  const base::Value* value = nullptr;
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
 
   settings_.reset();
   settings_service_.SetLocalSetting(
       kSettingsName,
       scoped_ptr<base::Value>(new base::StringValue(kSettingsValue)));
   ASSERT_TRUE(settings_);
   ASSERT_TRUE(settings_->GetWithoutPathExpansion(kSettingsName, &value));
   std::string string_value;
   EXPECT_TRUE(value->GetAsString(&string_value));
@@ skipping 60 matching lines @@
   EXPECT_EQ(syncer::SyncChange::ACTION_UPDATE, change.change_type());
   VerifySyncDataItem(change.sync_data());
 
   sync_data = settings_service_.GetAllSyncData(
       syncer::SUPERVISED_USER_SETTINGS);
   EXPECT_EQ(4u, sync_data.size());
   for (const syncer::SyncData& sync_data_item : sync_data)
     VerifySyncDataItem(sync_data_item);
 
   // The uploaded items should not show up as settings.
-  const base::Value* value = NULL;
+  const base::Value* value = nullptr;
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kAtomicItemName, &value));
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kSplitItemName, &value));
 
   // Restarting sync should not create any new changes.
   settings_service_.StopSyncing(syncer::SUPERVISED_USER_SETTINGS);
   StartSyncing(sync_data);
   ASSERT_EQ(0u, sync_processor_->changes().size());
 }