Return resources immediately after a Surface is destroyed

cc/surfaces/surface_synchronization_unittest.cc

Index: cc/surfaces/surface_synchronization_unittest.cc
diff --git a/cc/surfaces/surface_synchronization_unittest.cc b/cc/surfaces/surface_synchronization_unittest.cc
index 473e5876f2e33d76de3f09df814f448b58f41fe1..f691c4ed3fa7e9a987c86a1d3ff06047d99edd2e 100644
--- a/cc/surfaces/surface_synchronization_unittest.cc
+++ b/cc/surfaces/surface_synchronization_unittest.cc
@@ -155,6 +155,7 @@ class SurfaceSynchronizationTest : public testing::Test,
   void OnSurfaceDamaged(const SurfaceId& surface_id, bool* changed) override {
     damaged_surfaces_.insert(surface_id);
   }
+  void OnSurfaceDiscarded(const SurfaceId& surface_id) override {}
 
  protected:
   testing::NiceMock<MockCompositorFrameSinkSupportClient> support_client_;