PushPropertiesCountingLayer tracks PushPropertiesTo calls in layer_tree_host_unittests.cc, but this will not work for remote LTH, since it does not directly call PushPropertiesTo but call ToLayerPropertiesProto to do the serialization.

We will consider to override PushPropertiesCountingLayer::ToLayerPropertiesProto
to call PushPropertiesTo to ensure the test cases also apply for remote test.