Disable DCHECK in property_tree.cc, layer_tree_impl.cc

Certain DCHECKs may trigger when an element in a PropertyTree is being
animated, while at the same time the user is rapidly scrolling the
web page. Comments in related code seem to indicate these DCHECKs
were put in place to investigate cases where nonexistent tree nodes
were being animated. The code surrounding them seems to be guarded
against such cases, so they should be safe to disable.

These seem to be triggerable in upstream Chromium as well:
https://issues.chromium.org/issues/40226717

Task-number: QTBUG-122924
Change-Id: I9ba49272714467beff30cb4671e78542fe7e4bda
Reviewed-on: https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/568625
Reviewed-by: Peter Varga <pvarga@inf.u-szeged.hu>
(cherry picked from commit 03019ab)
Reviewed-on: https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/622866
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

Author: Kaloyan Chehlarski

chromium/cc/trees/layer_tree_impl.cc

@@ -949,9 +949,9 @@ ElementListType LayerTreeImpl::GetElementTypeForAnimation() const {
 
 void LayerTreeImpl::SetTransformMutated(ElementId element_id,
                                         const gfx::Transform& transform) {
-  DCHECK_EQ(1u,
-            property_trees()->transform_tree().element_id_to_node_index().count(
-                element_id));
+  // DCHECK_EQ(1u,
+  //           property_trees()->transform_tree().element_id_to_node_index().count(
+  //               element_id));
   if (!base::FeatureList::IsEnabled(features::kNoPreserveLastMutation) &&
       (IsSyncTree() || IsRecycleTree())) {
     element_id_to_transform_animations_[element_id] = transform;
@@ -962,9 +962,9 @@ void LayerTreeImpl::SetTransformMutated(ElementId element_id,
 }
 
 void LayerTreeImpl::SetOpacityMutated(ElementId element_id, float opacity) {
-  DCHECK_EQ(1u,
-            property_trees()->effect_tree().element_id_to_node_index().count(
-                element_id));
+  // DCHECK_EQ(1u,
+  //           property_trees()->effect_tree().element_id_to_node_index().count(
+  //               element_id));
   if (!base::FeatureList::IsEnabled(features::kNoPreserveLastMutation) &&
       (IsSyncTree() || IsRecycleTree())) {
     element_id_to_opacity_animations_[element_id] = opacity;
@@ -976,9 +976,9 @@ void LayerTreeImpl::SetOpacityMutated(ElementId element_id, float opacity) {
 
 void LayerTreeImpl::SetFilterMutated(ElementId element_id,
                                      const FilterOperations& filters) {
-  DCHECK_EQ(1u,
-            property_trees()->effect_tree().element_id_to_node_index().count(
-                element_id));
+  // DCHECK_EQ(1u,
+  //           property_trees()->effect_tree().element_id_to_node_index().count(
+  //               element_id));
   if (!base::FeatureList::IsEnabled(features::kNoPreserveLastMutation) &&
       (IsSyncTree() || IsRecycleTree())) {
     element_id_to_filter_animations_[element_id] = filters;
@@ -991,9 +991,9 @@ void LayerTreeImpl::SetFilterMutated(ElementId element_id,
 void LayerTreeImpl::SetBackdropFilterMutated(
     ElementId element_id,
     const FilterOperations& backdrop_filters) {
-  DCHECK_EQ(1u,
-            property_trees()->effect_tree().element_id_to_node_index().count(
-                element_id));
+  // DCHECK_EQ(1u,
+  //           property_trees()->effect_tree().element_id_to_node_index().count(
+  //               element_id));
   if (!base::FeatureList::IsEnabled(features::kNoPreserveLastMutation) &&
       (IsSyncTree() || IsRecycleTree())) {
     element_id_to_backdrop_filter_animations_[element_id] = backdrop_filters;

chromium/cc/trees/property_tree.cc

@@ -2128,9 +2128,9 @@ bool PropertyTrees::ElementIsAnimatingChanged(
             effect_tree_mutable().set_needs_update(true);
           }
         } else {
-          DCHECK_NODE_EXISTENCE(check_node_existence, state, property,
-                                needs_rebuild())
-              << "Attempting to animate opacity on non existent effect node";
+          // DCHECK_NODE_EXISTENCE(check_node_existence, state, property,
+          //                       needs_rebuild())
+          //     << "Attempting to animate opacity on non existent effect node";
         }
         break;
       case TargetProperty::FILTER:
@@ -2145,9 +2145,9 @@ bool PropertyTrees::ElementIsAnimatingChanged(
           // Filter animation changes only the node, and the subtree does not
           // care, thus there is no need to request property tree update.
         } else {
-          DCHECK_NODE_EXISTENCE(check_node_existence, state, property,
-                                needs_rebuild())
-              << "Attempting to animate filter on non existent effect node";
+          // DCHECK_NODE_EXISTENCE(check_node_existence, state, property,
+          //                       needs_rebuild())
+          //     << "Attempting to animate filter on non existent effect node";
         }
         break;
       case TargetProperty::BACKDROP_FILTER:
@@ -2163,9 +2163,9 @@ bool PropertyTrees::ElementIsAnimatingChanged(
           // does not care, thus there is no need to request property tree
           // update.
         } else {
-          DCHECK_NODE_EXISTENCE(check_node_existence, state, property,
-                                needs_rebuild())
-              << "Attempting to animate filter on non existent effect node";
+          // DCHECK_NODE_EXISTENCE(check_node_existence, state, property,
+          //                       needs_rebuild())
+          //     << "Attempting to animate filter on non existent effect node";
         }
         break;
       default: