Build property trees for the HUD layer when using layer lists

cc/trees/layer_tree_host.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.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 637 matching lines @@
 
   Layer* root_scroll =
       PropertyTreeBuilder::FindFirstScrollableLayer(root_layer);
   Layer* page_scale_layer = page_scale_layer_.get();
   if (!page_scale_layer && root_scroll)
     page_scale_layer = root_scroll->parent();
 
   if (hud_layer_) {
     hud_layer_->PrepareForCalculateDrawProperties(device_viewport_size_,
                                                   device_scale_factor_);
+    // The HUD layer is managed outside the layer list sent to LayerTreeHost
+    // and needs to have its property tree state set.
+    if (settings_.use_layer_lists && root_layer_.get()) {
+      hud_layer_->SetTransformTreeIndex(root_layer_->transform_tree_index());
+      hud_layer_->SetEffectTreeIndex(root_layer_->effect_tree_index());
+      hud_layer_->SetClipTreeIndex(root_layer_->clip_tree_index());
+      hud_layer_->SetScrollTreeIndex(root_layer_->scroll_tree_index());
+      hud_layer_->set_property_tree_sequence_number(
+          root_layer_->property_tree_sequence_number());
+    }
   }
 
   gfx::Transform identity_transform;
   LayerList update_layer_list;
 
   {
     base::AutoReset<bool> update_property_trees(&in_update_property_trees_,
                                                 true);
     TRACE_EVENT0("cc",
                  "LayerTreeHostInProcess::UpdateLayers::BuildPropertyTrees");
@@ skipping 678 matching lines @@
 LayerListReverseIterator<Layer> LayerTreeHost::rend() {
   return LayerListReverseIterator<Layer>(nullptr);
 }
 
 void LayerTreeHost::SetNeedsDisplayOnAllLayers() {
   for (auto* layer : *this)
     layer->SetNeedsDisplay();
 }
 
 }  // namespace cc