cc: DCHECK that the OutputSurface was released in ~LayerTreeHostImpl().

cc/trees/occlusion_tracker_unittest.cc

 // Copyright 2012 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/trees/occlusion_tracker.h"
 
 #include <stddef.h>
 
 #include "cc/base/math_util.h"
 #include "cc/layers/layer.h"
@@ skipping 180 matching lines @@
                                              const gfx::PointF& position,
                                              const gfx::Size& bounds,
                                              bool opaque) {
     TestContentLayerImpl* layer =
         CreateDrawingLayer(parent, transform, position, bounds, opaque);
     layer->test_properties()->force_render_surface = true;
     return layer;
   }
 
   void DestroyLayers() {
+    host_->host_impl()->active_tree()->ClearLayerList();
     host_->host_impl()->active_tree()->SetRootLayer(nullptr);
     render_surface_layer_list_impl_.clear();
     replica_layers_.clear();
     mask_layers_.clear();
     ResetLayerIterator();
   }
 
   void CopyOutputCallback(std::unique_ptr<CopyOutputResult> result) {}
 
   void AddCopyRequest(Layer* layer) {
@@ skipping 2303 matching lines @@
     EXPECT_EQ(gfx::Rect(),
               occlusion.UnoccludedSurfaceContentRect(
                   surface, gfx::Rect(80, 70, 50, 50)));
   }
 };
 
 ALL_OCCLUSIONTRACKER_TEST(OcclusionTrackerTestUnoccludedSurfaceQuery)
 
 }  // namespace
 }  // namespace cc