Return resources immediately after a Surface is destroyed

cc/surfaces/compositor_frame_sink_support_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 "cc/surfaces/compositor_frame_sink_support.h"
 
 #include "base/macros.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
@@ skipping 105 matching lines @@
   }
 
   // SurfaceObserver implementation.
   void OnSurfaceCreated(const SurfaceInfo& surface_info) override {
     last_created_surface_id_ = surface_info.id();
     last_surface_info_ = surface_info;
   }
   void OnSurfaceDamaged(const SurfaceId& id, bool* changed) override {
     *changed = true;
   }
+  void OnSurfaceDiscarded(const SurfaceId& surface_id) override {}
 
   void SubmitCompositorFrameWithResources(ResourceId* resource_ids,
                                           size_t num_resource_ids) {
     CompositorFrame frame = MakeCompositorFrame();
     for (size_t i = 0u; i < num_resource_ids; ++i) {
       TransferableResource resource;
       resource.id = resource_ids[i];
       resource.mailbox_holder.texture_target = GL_TEXTURE_2D;
       resource.mailbox_holder.sync_token = frame_sync_token_;
       frame.resource_list.push_back(resource);
@@ skipping 646 matching lines @@
   EXPECT_EQ(expected_surface_id, last_surface_info_.id());
   EXPECT_EQ(2.5f, last_surface_info_.device_scale_factor());
   EXPECT_EQ(gfx::Size(7, 8), last_surface_info_.size_in_pixels());
 }
 
 }  // namespace
 
 }  // namespace test
 
 }  // namespace cc