Fixes bug in ServerWindowCompositorFrameSinkManager

services/ui/ws/server_window.cc

Index: services/ui/ws/server_window.cc
diff --git a/services/ui/ws/server_window.cc b/services/ui/ws/server_window.cc
index 8ca546123ef56e2dfa22452edc5c583a039fb61c..1bc57d32b514bc7a3d6bb4a391c17d36aa92807d 100644
--- a/services/ui/ws/server_window.cc
+++ b/services/ui/ws/server_window.cc
@@ -15,7 +15,6 @@
 #include "services/ui/ws/server_window_observer.h"
 
 namespace ui {
-
 namespace ws {
 
 ServerWindow::ServerWindow(ServerWindowDelegate* delegate, const WindowId& id)
@@ -115,12 +114,18 @@ void ServerWindow::Add(ServerWindow* child) {
   for (auto& observer : child->observers_)
     observer.OnWillChangeWindowHierarchy(child, this, old_parent);
 
+  ServerWindow* old_root = child->GetRoot();
+  ServerWindow* new_root = GetRoot();
+
   if (child->parent())
     child->parent()->RemoveImpl(child);
 
   child->parent_ = this;
   children_.push_back(child);
 
+  if (old_root != new_root)
+    child->ProcessRootChanged(old_root, new_root);
+
   // Stack the child properly if it is a transient child of a sibling.
   if (child->transient_parent_ && child->transient_parent_->parent() == this)
     RestackTransientDescendants(child->transient_parent_, &GetStackingTarget,
@@ -419,6 +424,14 @@ void ServerWindow::RemoveImpl(ServerWindow* window) {
   children_.erase(std::find(children_.begin(), children_.end(), window));
 }
 
+void ServerWindow::ProcessRootChanged(ServerWindow* old_root,
+                                      ServerWindow* new_root) {
+  if (compositor_frame_sink_manager_)
+    compositor_frame_sink_manager_->OnRootChanged(old_root, new_root);
+  for (ServerWindow* child : children_)
+    child->ProcessRootChanged(old_root, new_root);
+}
+
 void ServerWindow::OnStackingChanged() {
   if (stacking_target_) {
     Windows::const_iterator window_i = std::find(
@@ -467,5 +480,4 @@ ServerWindow** ServerWindow::GetStackingTarget(ServerWindow* window) {
 }
 
 }  // namespace ws
-
 }  // namespace ui