Return resources immediately after a Surface is destroyed

cc/surfaces/surface_synchronization_unittest.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/containers/flat_set.h"
 #include "cc/surfaces/compositor_frame_sink_support.h"
 #include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surface_manager.h"
 #include "cc/surfaces/surface_observer.h"
 #include "cc/test/begin_frame_args_test.h"
@@ skipping 137 matching lines @@
 
   bool IsSurfaceDamaged(const SurfaceId& surface_id) const {
     return damaged_surfaces_.count(surface_id) > 0;
   }
 
   // SurfaceObserver implementation:
   void OnSurfaceCreated(const SurfaceInfo& surface_info) override {}
   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_;
 
  private:
   base::flat_set<SurfaceId> damaged_surfaces_;
   SurfaceManager surface_manager_;
   std::unique_ptr<FakeExternalBeginFrameSource> begin_frame_source_;
   std::vector<std::unique_ptr<CompositorFrameSinkSupport>> supports_;
 
@@ skipping 1213 matching lines @@
               DidReceiveCompositorFrameAck(Eq(returned_resources2)));
   child_support1().SubmitCompositorFrame(
       child_id1.local_surface_id(),
       MakeCompositorFrame(empty_surface_ids(), empty_surface_ids(),
                           {resource2}));
   testing::Mock::VerifyAndClearExpectations(&support_client_);
 }
 
 }  // namespace test
 }  // namespace cc