Revert "Revert 182527" ([Sync] Make SESSIONS an implicit type)

chrome/browser/sync/profile_sync_service_harness.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 "chrome/browser/sync/profile_sync_service_harness.h"
 
 #include <cstddef>
 #include <iterator>
 #include <ostream>
 #include <set>
@@ skipping 944 matching lines @@
   }
 
   syncer::ModelTypeSet synced_datatypes = service()->GetPreferredDataTypes();
   if (!synced_datatypes.Has(datatype)) {
     DVLOG(1) << "DisableSyncForDatatype(): Sync already disabled for datatype "
              << syncer::ModelTypeToString(datatype)
              << " on " << profile_debug_name_ << ".";
     return true;
   }
 
+  synced_datatypes.RetainAll(syncer::UserSelectableTypes());
   synced_datatypes.Remove(datatype);
   service()->OnUserChoseDatatypes(false, synced_datatypes);
   if (AwaitFullSyncCompletion("Datatype reconfiguration.")) {
     DVLOG(1) << "DisableSyncForDatatype(): Disabled sync for datatype "
              << syncer::ModelTypeToString(datatype)
              << " on " << profile_debug_name_ << ".";
     return true;
   }
 
   DVLOG(0) << GetClientInfoString("DisableSyncForDatatype failed");
@@ skipping 164 matching lines @@
 
 std::string ProfileSyncServiceHarness::GetServiceStatus() {
   scoped_ptr<DictionaryValue> value(
       sync_ui_util::ConstructAboutInformation(service_));
   std::string service_status;
   base::JSONWriter::WriteWithOptions(value.get(),
                                      base::JSONWriter::OPTIONS_PRETTY_PRINT,
                                      &service_status);
   return service_status;
 }