cc: Change how/when we build layer list/property tress in tests.

cc/trees/layer_tree_impl.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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 247 matching lines @@
 }
 
 bool LayerTreeImpl::LayerListIsEmpty() const {
   return layer_list_.empty();
 }
 
 void LayerTreeImpl::SetRootLayerForTesting(std::unique_ptr<LayerImpl> layer) {
   if (root_layer_for_testing_ && layer.get() != root_layer_for_testing_)
     RemoveLayer(root_layer_for_testing_->id());
   root_layer_for_testing_ = layer.get();
-  if (layer)
+  ClearLayerList();
+  if (layer) {
     AddLayer(std::move(layer));
-  BuildLayerListForTesting();
+    BuildLayerListForTesting();
+  }
   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 }
 
 void LayerTreeImpl::SetRootLayerFromLayerListForTesting() {
   root_layer_for_testing_ = layer_list_.empty() ? nullptr : layer_list_[0];
 }
 
 void LayerTreeImpl::OnCanDrawStateChangedForTree() {
   layer_tree_host_impl_->OnCanDrawStateChangedForTree();
 }
@@ skipping 734 matching lines @@
                      "layers_updated_count", layers_updated_count);
   }
 
   DCHECK(!needs_update_draw_properties_)
       << "CalcDrawProperties should not set_needs_update_draw_properties()";
   return true;
 }
 
 void LayerTreeImpl::BuildLayerListAndPropertyTreesForTesting() {
   BuildLayerListForTesting();
-  PropertyTreeBuilder::PreCalculateMetaInformationForTesting(
-      root_layer_for_testing_);
+  BuildPropertyTreesForTesting();
+}
+
+void LayerTreeImpl::BuildPropertyTreesForTesting() {
+  PropertyTreeBuilder::PreCalculateMetaInformationForTesting(layer_list_[0]);
+  property_trees_.needs_rebuild = true;
   property_trees_.transform_tree.set_source_to_parent_updates_allowed(true);
   PropertyTreeBuilder::BuildPropertyTrees(
-      root_layer_for_testing_, PageScaleLayer(), InnerViewportScrollLayer(),
+      layer_list_[0], PageScaleLayer(), InnerViewportScrollLayer(),
       OuterViewportScrollLayer(), OverscrollElasticityLayer(),
       elastic_overscroll()->Current(IsActiveTree()),
       current_page_scale_factor(), device_scale_factor(),
       gfx::Rect(DrawViewportSize()), layer_tree_host_impl_->DrawTransform(),
       &property_trees_);
   property_trees_.transform_tree.set_source_to_parent_updates_allowed(false);
 }
 
 const LayerImplList& LayerTreeImpl::RenderSurfaceLayerList() const {
   // If this assert triggers, then the list is dirty.
@@ skipping 1051 matching lines @@
 
 void LayerTreeImpl::ResetAllChangeTracking() {
   layers_that_should_push_properties_.clear();
   // Iterate over all layers, including masks and replicas.
   for (auto& layer : *layers_)
     layer->ResetChangeTracking();
   property_trees_.ResetAllChangeTracking();
 }
 
 }  // namespace cc