cc: Simplify the logic for deciding to update tile priorities.

cc/trees/occlusion_tracker_unittest.cc

Index: cc/trees/occlusion_tracker_unittest.cc
diff --git a/cc/trees/occlusion_tracker_unittest.cc b/cc/trees/occlusion_tracker_unittest.cc
index 72e0ea052d025a3b0c200a5a85d0df529533c2f2..1daf5419927b73a1a3175e5293dd699988fad9ec 100644
--- a/cc/trees/occlusion_tracker_unittest.cc
+++ b/cc/trees/occlusion_tracker_unittest.cc
@@ -321,8 +321,7 @@ template <typename Types> class OcclusionTrackerTest : public testing::Test {
         NULL,
         dummy_max_texture_size,
         false,
-        &render_surface_layer_list_impl_,
-        false);
+        &render_surface_layer_list_impl_);
 
     layer_iterator_ = layer_iterator_begin_ =
         Types::TestLayerIterator::Begin(&render_surface_layer_list_impl_);