cc: Make sure we don't insert or remove layers during painting

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 <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 100 matching lines @@
       gpu_rasterization_histogram_recorded_(false),
       background_color_(SK_ColorWHITE),
       has_transparent_background_(false),
       did_complete_scale_animation_(false),
       in_paint_layer_contents_(false),
       id_(s_layer_tree_host_sequence_number.GetNext() + 1),
       next_commit_forces_redraw_(false),
       shared_bitmap_manager_(params->shared_bitmap_manager),
       gpu_memory_buffer_manager_(params->gpu_memory_buffer_manager),
       task_graph_runner_(params->task_graph_runner),
+      in_update_(false),
       surface_id_namespace_(0u),
       next_surface_sequence_(1u) {
   DCHECK(task_graph_runner_);
 
   if (settings_.accelerated_animation_enabled) {
     if (settings_.use_compositor_animation_timelines) {
       animation_host_ = AnimationHost::Create(ThreadInstance::MAIN);
       animation_host_->SetMutatorHostClient(this);
     } else {
       animation_registrar_ = AnimationRegistrar::Create();
@@ skipping 658 matching lines @@
     BuildPropertyTreesAndComputeVisibleRects(
         root_layer, page_scale_layer, inner_viewport_scroll_layer_.get(),
         outer_viewport_scroll_layer_.get(), page_scale_factor_,
         device_scale_factor_, gfx::Rect(device_viewport_size_),
         identity_transform, &property_trees_, &update_layer_list);
   }
 
   for (const auto& layer : update_layer_list)
     layer->SavePaintProperties();
 
+  in_update_ = true;
   base::AutoReset<bool> painting(&in_paint_layer_contents_, true);
   bool did_paint_content = false;
   for (const auto& layer : update_layer_list) {
     // TODO(enne): temporarily clobber draw properties visible rect.
     layer->draw_properties().visible_layer_rect =
         layer->visible_rect_from_property_trees();
     did_paint_content |= layer->Update();
     content_is_suitable_for_gpu_rasterization_ &=
         layer->IsSuitableForGpuRasterization();
   }
+  in_update_ = false;
   return did_paint_content;
 }
 
 void LayerTreeHost::ReduceMemoryUsage() {
   if (!root_layer())
     return;
 
   LayerTreeHostCommon::CallFunctionForSubtree(
       root_layer(), [](Layer* layer) { layer->ReduceMemoryUsage(); });
 }
@@ skipping 388 matching lines @@
   return animation_host_ ? animation_host_->HasAnyAnimation(layer->id())
                          : false;
 }
 
 bool LayerTreeHost::HasActiveAnimation(const Layer* layer) const {
   return animation_host_ ? animation_host_->HasActiveAnimation(layer->id())
                          : false;
 }
 
 }  // namespace cc