[Sync] Return nullptr for OpenTabsUIDelegate when PROXY_TABS is disabled.

components/browser_sync/profile_sync_service_unittest.cc

 // Copyright (c) 2012 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/browser_sync/profile_sync_service.h"
 
 #include <utility>
 
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 21 matching lines @@
 #include "components/sync/driver/sync_driver_switches.h"
 #include "components/sync/driver/sync_service_observer.h"
 #include "components/sync/driver/sync_util.h"
 #include "components/sync_preferences/testing_pref_service_syncable.h"
 #include "components/version_info/version_info_values.h"
 #include "google_apis/gaia/gaia_constants.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/l10n/l10n_util.h"
 
+using syncer::DataTypeController;
 using syncer::SyncBackendHostMock;
+using syncer::SyncMergeResult;
 using testing::Return;
 
 namespace browser_sync {
 
 namespace {
 
 const char kGaiaId[] = "12345";
 const char kEmail[] = "test_user@gmail.com";
 
 class FakeDataTypeManager : public syncer::DataTypeManager {
@@ skipping 139 matching lines @@
     syncer::SyncManager::ClearServerDataCallback* captured_callback,
     const syncer::SyncManager::ClearServerDataCallback& callback) {
   *captured_callback = callback;
 }
 
 ACTION_P(ReturnNewMockHostCaptureClearServerData, captured_callback) {
   return new SyncBackendHostCaptureClearServerData(base::Bind(
       &OnClearServerDataCalled, base::Unretained(captured_callback)));
 }
 
+void DoNothing(DataTypeController::ConfigureResult ignored1,
+               const SyncMergeResult& ignored2,
+               const SyncMergeResult& ignored3) {}
+
 // A test harness that uses a real ProfileSyncService and in most cases a
 // MockSyncBackendHost.
 //
 // This is useful if we want to test the ProfileSyncService and don't care about
 // testing the SyncBackendHost.
 class ProfileSyncServiceTest : public ::testing::Test {
  protected:
   ProfileSyncServiceTest() : component_factory_(nullptr) {}
   ~ProfileSyncServiceTest() override {}
 
@@ skipping 733 matching lines @@
 // Regression test for crbug/555434. The issue is that check for sessions DTC in
 // OnSessionRestoreComplete was creating map entry with nullptr which later was
 // dereferenced in OnSyncCycleCompleted. The fix is to use find() to check if
 // entry for sessions exists in map.
 TEST_F(ProfileSyncServiceTest, ValidPointersInDTCMap) {
   CreateService(ProfileSyncService::AUTO_START);
   service()->OnSessionRestoreComplete();
   service()->OnSyncCycleCompleted();
 }
 
+// The OpenTabsUIDelegate should only be accessable when PROXY_TABS is enabled.
+TEST_F(ProfileSyncServiceTest, GetOpenTabsUIDelegate) {
+  CreateService(ProfileSyncService::AUTO_START);
+  InitializeForNthSync();
+  EXPECT_EQ(nullptr, service()->GetOpenTabsUIDelegate());
+
+  auto controller =
+      base::MakeUnique<syncer::FakeDataTypeController>(syncer::PROXY_TABS);
+  // Progress the controller to RUNNING first, which is how the service
+  // determines whether a type is enabled.
+  controller->StartAssociating(base::Bind(&DoNothing));
+  controller->FinishStart(DataTypeController::OK_FIRST_RUN);
+  service()->RegisterDataTypeController(std::move(controller));
+  EXPECT_NE(nullptr, service()->GetOpenTabsUIDelegate());
+}
+
 }  // namespace
 }  // namespace browser_sync