cc: Get rid of LayerTreeHost::output_surface_lost_ state.

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index 701431eb20535acbb4056d7abb3160a82a0e2bdb..f83fceab4291cd359522c7465762c9a378915d01 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -387,10 +387,6 @@ class LayerTreeHostForTesting : public LayerTreeHost {
           proxy = ProxyMain::CreateRemote(remote_proto_channel,
                                           layer_tree_host.get(),
                                           task_runner_provider.get());
-
-          // The LayerTreeHost on the server will never have an output surface.
-          // Set output_surface_lost_ to false by default.
-          layer_tree_host->SetOutputSurfaceLostForTesting(false);
         }
         break;
     }