cc: Ensure damage in property tree nodes gets propagated to descendants

cc/trees/property_tree.cc

Index: cc/trees/property_tree.cc
diff --git a/cc/trees/property_tree.cc b/cc/trees/property_tree.cc
index de0096bca4ef9a192051c29a941135273c593540..216467641cc649d90dcf64c066adeb5e88d8f8a9 100644
--- a/cc/trees/property_tree.cc
+++ b/cc/trees/property_tree.cc
@@ -1892,6 +1892,20 @@ void PropertyTrees::SetInnerViewportScrollBoundsDelta(
   inner_viewport_scroll_bounds_delta_ = bounds_delta;
 }
 
+void PropertyTrees::UpdateChangeTracking() {
+  for (int id = 1; id < static_cast<int>(effect_tree.size()); ++id) {
+    EffectNode* node = effect_tree.Node(id);
+    EffectNode* parent_node = effect_tree.parent(node);
+    effect_tree.UpdateEffectChanged(node, parent_node);
+  }
+  for (int i = 1; i < static_cast<int>(transform_tree.size()); ++i) {
+    TransformNode* node = transform_tree.Node(i);
+    TransformNode* parent_node = transform_tree.parent(node);
+    TransformNode* source_node = transform_tree.Node(node->data.source_node_id);
+    transform_tree.UpdateTransformChanged(node, parent_node, source_node);
+  }
+}
+
 void PropertyTrees::PushChangeTrackingTo(PropertyTrees* tree) {
   for (int id = 1; id < static_cast<int>(effect_tree.size()); ++id) {
     EffectNode* node = effect_tree.Node(id);
@@ -1907,6 +1921,9 @@ void PropertyTrees::PushChangeTrackingTo(PropertyTrees* tree) {
       target_node->data.transform_changed = true;
     }
   }
+  // Ensure that change tracking is updated even if property trees don't have
+  // other reasons to get updated.
+  tree->UpdateChangeTracking();
   tree->full_tree_damaged = full_tree_damaged;
 }