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

cc/test/fake_layer_tree_host_impl.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/test/fake_layer_tree_host_impl.h"
 
 #include <stddef.h>
 
 #include "cc/animation/animation_host.h"
 #include "cc/test/begin_frame_args_test.h"
@@ skipping 44 matching lines @@
   // Explicitly clear all debug settings.
   SetDebugState(LayerTreeDebugState());
   SetViewportSize(gfx::Size(100, 100));
 
   // Start an impl frame so tests have a valid frame_time to work with.
   base::TimeTicks time_ticks = base::TimeTicks::FromInternalValue(1);
   WillBeginImplFrame(
       CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, time_ticks));
 }
 
-FakeLayerTreeHostImpl::~FakeLayerTreeHostImpl() {}
+FakeLayerTreeHostImpl::~FakeLayerTreeHostImpl() {
+  ReleaseOutputSurface();
+}
 
 void FakeLayerTreeHostImpl::CreatePendingTree() {
   LayerTreeHostImpl::CreatePendingTree();
   float arbitrary_large_page_scale = 100000.f;
   pending_tree()->PushPageScaleFromMainThread(
       1.f, 1.f / arbitrary_large_page_scale, arbitrary_large_page_scale);
 }
 
 void FakeLayerTreeHostImpl::NotifyTileStateChanged(const Tile* tile) {
   LayerTreeHostImpl::NotifyTileStateChanged(tile);
@@ skipping 28 matching lines @@
 
 void FakeLayerTreeHostImpl::UpdateNumChildrenAndDrawProperties(
     LayerTreeImpl* layerTree) {
   RecursiveUpdateNumChildren(layerTree->root_layer());
   bool update_lcd_text = false;
   layerTree->BuildLayerListAndPropertyTreesForTesting();
   layerTree->UpdateDrawProperties(update_lcd_text);
 }
 
 }  // namespace cc