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 19c968941d50c3dcfba19798b16f70541070a97f..6bd79e5615247fe68e7d235710cbe98ad870e630 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -391,10 +391,6 @@ 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;
     }