[Sync] Hook UserEvents into sync.

components/sync/user_events/user_event_service_unittest.cc

Index: components/sync/user_events/user_event_service_unittest.cc
diff --git a/components/sync/user_events/user_event_service_unittest.cc b/components/sync/user_events/user_event_service_unittest.cc
index 83e968a25e2f8dd6dca16807b3a2a0a18b703c27..f7862e6f1c0c40af2d42e010ef521935f53d015e 100644
--- a/components/sync/user_events/user_event_service_unittest.cc
+++ b/components/sync/user_events/user_event_service_unittest.cc
@@ -6,8 +6,10 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
+#include "base/test/scoped_feature_list.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/driver/fake_sync_service.h"
+#include "components/sync/driver/sync_driver_switches.h"
 #include "components/sync/model/model_type_store_test_util.h"
 #include "components/sync/model/recording_model_type_change_processor.h"
 #include "components/sync/protocol/sync.pb.h"
@@ -39,6 +41,11 @@ class TestSyncService : public FakeSyncService {
 
 class UserEventServiceTest : public testing::Test {
  protected:
+  UserEventServiceTest() {
+    scoped_feature_list_ = base::MakeUnique<base::test::ScopedFeatureList>();
+    scoped_feature_list_->InitAndEnableFeature(switches::kSyncUserEvents);
+  }
+
   std::unique_ptr<UserEventSyncBridge> MakeBridge() {
     return base::MakeUnique<UserEventSyncBridge>(
         ModelTypeStoreTestUtil::FactoryForInMemoryStoreForTest(),
@@ -47,7 +54,13 @@ class UserEventServiceTest : public testing::Test {
 
   const RecordingModelTypeChangeProcessor& processor() { return *processor_; }
 
+  void DisableUserEvents() {
+    scoped_feature_list_ = base::MakeUnique<base::test::ScopedFeatureList>();
+    scoped_feature_list_->Init();
+  }
+
  private:
+  std::unique_ptr<base::test::ScopedFeatureList> scoped_feature_list_;
   RecordingModelTypeChangeProcessor* processor_;
   base::MessageLoop message_loop_;
 };
@@ -58,6 +71,14 @@ TEST_F(UserEventServiceTest, ShouldNotRecordNoSync) {
   EXPECT_EQ(0u, processor().put_multimap().size());
 }
 
+TEST_F(UserEventServiceTest, ShouldNotRecordFeatureIsDisabled) {
+  DisableUserEvents();
+  TestSyncService sync_service(false, ModelTypeSet(HISTORY_DELETE_DIRECTIVES));
+  UserEventService service(&sync_service, MakeBridge());
+  service.RecordUserEvent(base::MakeUnique<UserEventSpecifics>());
+  EXPECT_EQ(0u, processor().put_multimap().size());
+}
+
 TEST_F(UserEventServiceTest, ShouldNotRecordNoHistory) {
   TestSyncService sync_service(true, ModelTypeSet());
   UserEventService service(&sync_service, MakeBridge());