[Sync] Set HasCustomGroupsToChange() to true for ApplyUpdatesCommand

Follow-up to 113090 to see which ModelChangingSyncerCommand triggers
a perf regression.

BUG=97832
TEST=
TBR=tim@chromium.org

Review URL: http://codereview.chromium.org/8818019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113238 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/sync/engine/apply_updates_command.cc

@@ -18,8 +18,7 @@ ApplyUpdatesCommand::ApplyUpdatesCommand() {}
 ApplyUpdatesCommand::~ApplyUpdatesCommand() {}
 
 bool ApplyUpdatesCommand::HasCustomGroupsToChange() const {
-  // TODO(akalin): Set to true.
-  return false;
+  return true;
 }
 
 std::set<ModelSafeGroup> ApplyUpdatesCommand::GetGroupsToChange(