cc: Clean up root_layer code in LTI

cc/test/test_layer_tree_host_base.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/test/test_layer_tree_host_base.h"
 
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_raster_source.h"
 #include "cc/trees/layer_tree_impl.h"
 
@@ skipping 87 matching lines @@
     const gfx::Size& tile_size,
     const Region& invalidation) {
   host_impl()->CreatePendingTree();
   host_impl()->pending_tree()->PushPageScaleFromMainThread(1.f, 0.00001f,
                                                            100000.f);
   LayerTreeImpl* pending_tree = host_impl()->pending_tree();
   pending_tree->SetDeviceScaleFactor(
       host_impl()->active_tree()->device_scale_factor());
 
   // Steal from the recycled tree if possible.
-  LayerImpl* pending_root = pending_tree->root_layer();
+  LayerImpl* pending_root = pending_tree->root_layer_for_testing();
   std::unique_ptr<FakePictureLayerImpl> pending_layer;
   DCHECK(!pending_root || pending_root->id() == root_id_);
   if (!pending_root) {
     std::unique_ptr<LayerImpl> new_pending_root =
         LayerImpl::Create(pending_tree, root_id_);
     pending_layer = FakePictureLayerImpl::Create(pending_tree, id_);
     if (!tile_size.IsEmpty())
       pending_layer->set_fixed_tile_size(tile_size);
     pending_layer->SetDrawsContent(true);
     pending_layer->SetScrollClipLayer(new_pending_root->id());
     pending_root = new_pending_root.get();
-    pending_tree->SetRootLayer(std::move(new_pending_root));
+    pending_tree->SetRootLayerForTesting(std::move(new_pending_root));
   } else {
     pending_layer.reset(static_cast<FakePictureLayerImpl*>(
         pending_root->test_properties()
             ->RemoveChild(pending_root->test_properties()->children[0])
             .release()));
     if (!tile_size.IsEmpty())
       pending_layer->set_fixed_tile_size(tile_size);
   }
   pending_root->test_properties()->force_render_surface = true;
   // The bounds() just mirror the raster source size.
   pending_layer->SetBounds(raster_source->GetSize());
   pending_layer->SetRasterSourceOnPending(raster_source, invalidation);
 
   pending_root->test_properties()->AddChild(std::move(pending_layer));
-  pending_tree->SetViewportLayersFromIds(Layer::INVALID_ID,
-                                         pending_tree->root_layer()->id(),
-                                         Layer::INVALID_ID, Layer::INVALID_ID);
+  pending_tree->SetViewportLayersFromIds(
+      Layer::INVALID_ID, pending_tree->root_layer_for_testing()->id(),
+      Layer::INVALID_ID, Layer::INVALID_ID);
 
   pending_layer_ = static_cast<FakePictureLayerImpl*>(
       host_impl()->pending_tree()->LayerById(id_));
 
   // Add tilings/tiles for the layer.
   bool update_lcd_text = false;
   RebuildPropertyTreesOnPendingTree();
   host_impl()->pending_tree()->UpdateDrawProperties(update_lcd_text);
 }
 
@@ skipping 24 matching lines @@
   state.hard_memory_limit_in_bytes = state.soft_memory_limit_in_bytes * 2;
   state.memory_limit_policy = ALLOW_ANYTHING;
   state.tree_priority = SAME_PRIORITY_FOR_BOTH_TREES;
 
   host_impl_->resource_pool()->SetResourceUsageLimits(
       state.soft_memory_limit_in_bytes, state.num_resources_limit);
   host_impl_->tile_manager()->SetGlobalStateForTesting(state);
 }
 
 }  // namespace cc