Speculative revert by sheriff

cc/trees/layer_tree_host_common_unittest.cc

 // Copyright 2011 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/layer_tree_host_common.h"
 
 #include <algorithm>
 #include <set>
 
 #include "cc/animation/layer_animation_controller.h"
@@ skipping 42 matching lines @@
 
 bool LayerWithForcedDrawsContent::DrawsContent() const { return true; }
 
 class MockContentLayerClient : public ContentLayerClient {
  public:
   MockContentLayerClient() {}
   ~MockContentLayerClient() override {}
   void PaintContents(SkCanvas* canvas,
                      const gfx::Rect& clip,
                      PaintingControlSetting picture_control) override {}
-  void PaintContentsToDisplayList(
-      DisplayItemList* display_list,
+  scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
       const gfx::Rect& clip,
       PaintingControlSetting picture_control) override {
     NOTIMPLEMENTED();
+    return DisplayItemList::Create();
   }
   bool FillsBoundsCompletely() const override { return false; }
 };
 
 scoped_refptr<FakePictureLayer> CreateDrawablePictureLayer(
     ContentLayerClient* delegate) {
   scoped_refptr<FakePictureLayer> to_return =
       FakePictureLayer::Create(delegate);
   to_return->SetIsDrawable(true);
   return to_return;
@@ skipping 9078 matching lines @@
   host->SetRootLayer(root);
 
   ExecuteCalculateDrawProperties(root.get());
 
   gfx::Rect expected(0, 0, 50, 50);
   EXPECT_EQ(expected, fixed->visible_rect_from_property_trees());
 }
 
 }  // namespace
 }  // namespace cc