cc: Clean up root_layer code in LTI

cc/layers/layer_list_iterator_unittest.cc

 // Copyright 2016 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/layers/layer_list_iterator.h"
 
 #include <memory>
 
 #include "base/containers/adapters.h"
 #include "cc/test/fake_impl_task_runner_provider.h"
@@ skipping 221 matching lines @@
 
   layer2->test_properties()->AddChild(std::move(layer3));
   layer2->test_properties()->AddChild(std::move(layer4));
 
   layer5->test_properties()->AddChild(std::move(layer6));
   layer5->test_properties()->AddChild(std::move(layer7));
 
   layer1->test_properties()->AddChild(std::move(layer2));
   layer1->test_properties()->AddChild(std::move(layer5));
 
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 1;
   for (auto* layer : *host_impl.active_tree()) {
     EXPECT_EQ(i++, layer->id());
   }
   EXPECT_EQ(8, i);
 }
 
 TEST(LayerListIteratorTest, VerifySingleLayerImpl) {
   // Unfortunate preamble.
   FakeImplTaskRunnerProvider task_runner_provider;
   TestSharedBitmapManager shared_bitmap_manager;
   TestTaskGraphRunner task_graph_runner;
   std::unique_ptr<OutputSurface> output_surface = FakeOutputSurface::Create3d();
   FakeLayerTreeHostImpl host_impl(&task_runner_provider, &shared_bitmap_manager,
                                   &task_graph_runner);
   host_impl.SetVisible(true);
   EXPECT_TRUE(host_impl.InitializeRenderer(output_surface.get()));
 
   // This test constructs a tree consisting of a single layer.
   std::unique_ptr<LayerImpl> layer1 =
       LayerImpl::Create(host_impl.active_tree(), 1);
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 1;
   for (auto* layer : *host_impl.active_tree()) {
     EXPECT_EQ(i++, layer->id());
   }
   EXPECT_EQ(2, i);
 }
 
 TEST(LayerListIteratorTest, VerifyNullFirstLayerImpl) {
@@ skipping 45 matching lines @@
 
   layer2->test_properties()->AddChild(std::move(layer3));
   layer2->test_properties()->AddChild(std::move(layer4));
 
   layer5->test_properties()->AddChild(std::move(layer6));
   layer5->test_properties()->AddChild(std::move(layer7));
 
   layer1->test_properties()->AddChild(std::move(layer2));
   layer1->test_properties()->AddChild(std::move(layer5));
 
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 7;
 
   for (auto* layer : base::Reversed(*host_impl.active_tree())) {
     EXPECT_EQ(i--, layer->id());
   }
 
   EXPECT_EQ(0, i);
 }
 
 TEST(LayerListReverseIteratorTest, VerifySingleLayerImpl) {
   // Unfortunate preamble.
   FakeImplTaskRunnerProvider task_runner_provider;
   TestSharedBitmapManager shared_bitmap_manager;
   TestTaskGraphRunner task_graph_runner;
   std::unique_ptr<OutputSurface> output_surface = FakeOutputSurface::Create3d();
   FakeLayerTreeHostImpl host_impl(&task_runner_provider, &shared_bitmap_manager,
                                   &task_graph_runner);
   host_impl.SetVisible(true);
   EXPECT_TRUE(host_impl.InitializeRenderer(output_surface.get()));
 
   // This test constructs a tree consisting of a single layer.
   std::unique_ptr<LayerImpl> layer1 =
       LayerImpl::Create(host_impl.active_tree(), 1);
-  host_impl.active_tree()->SetRootLayer(std::move(layer1));
+  host_impl.active_tree()->SetRootLayerForTesting(std::move(layer1));
   host_impl.active_tree()->BuildLayerListForTesting();
 
   int i = 1;
   for (auto* layer : base::Reversed(*host_impl.active_tree())) {
     EXPECT_EQ(i--, layer->id());
   }
   EXPECT_EQ(0, i);
 }
 
 TEST(LayerListReverseIteratorTest, VerifyNullFirstLayerImpl) {
   // Ensures that if an iterator is constructed with a nullptr, that it can be
   // iterated without issue and that it remains equal to any other
   // null-initialized iterator.
   LayerListReverseIterator<LayerImpl> it(nullptr);
   LayerListReverseIterator<LayerImpl> end(nullptr);
 
   EXPECT_EQ(it, end);
   ++it;
   EXPECT_EQ(it, end);
 }
 
 }  // namespace
 }  // namespace cc