cc: Clean up root_layer code in LTI

cc/layers/render_surface_impl_unittest.cc

 // Copyright 2014 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/render_surface_impl.h"
 
 #include <stddef.h>
 
 #include "cc/layers/append_quads_data.h"
 #include "cc/quads/render_pass_draw_quad.h"
@@ skipping 75 matching lines @@
   surface->test_properties()->mask_layer->SetDrawsContent(true);
   surface->test_properties()->mask_layer->SetBounds(layer_size);
 
   std::unique_ptr<LayerImpl> child =
       LayerImpl::Create(impl.host_impl()->active_tree(), 5);
   child->SetDrawsContent(true);
   child->SetBounds(layer_size);
 
   surface->test_properties()->AddChild(std::move(child));
   root->test_properties()->AddChild(std::move(surface));
-  impl.host_impl()->active_tree()->SetRootLayer(std::move(root));
+  impl.host_impl()->active_tree()->SetRootLayerForTesting(std::move(root));
 
   impl.host_impl()->SetViewportSize(viewport_size);
   impl.host_impl()->active_tree()->BuildLayerListAndPropertyTreesForTesting();
   impl.host_impl()->active_tree()->UpdateDrawProperties(false);
 
   LayerImpl* surface_raw = impl.host_impl()
                                ->active_tree()
-                               ->root_layer()
+                               ->root_layer_for_testing()
                                ->test_properties()
                                ->children[0];
   RenderSurfaceImpl* render_surface_impl = surface_raw->render_surface();
   std::unique_ptr<RenderPass> render_pass = RenderPass::Create();
   AppendQuadsData append_quads_data;
   render_surface_impl->AppendQuads(
       render_pass.get(), render_surface_impl->draw_transform(), Occlusion(),
       SK_ColorBLACK, 1.f, render_surface_impl->MaskLayer(), &append_quads_data,
       RenderPassId(1, 1));
 
   const RenderPassDrawQuad* quad =
       RenderPassDrawQuad::MaterialCast(render_pass->quad_list.front());
   EXPECT_EQ(gfx::Vector2dF(0.0005f, 0.0005f), quad->mask_uv_scale);
   EXPECT_EQ(gfx::Vector2dF(2.f, 2.f), quad->filters_scale);
 }
 
 }  // namespace
 }  // namespace cc