Changes OnWindowHierarchyChanged() to include transient parent

services/ui/ws/window_tree.cc

 // Copyright 2014 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 "services/ui/ws/window_tree.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 996 matching lines @@
   std::vector<mojom::WindowDataPtr> array(windows.size());
   for (size_t i = 0; i < windows.size(); ++i)
     array[i] = WindowToWindowData(windows[i]);
   return array;
 }
 
 mojom::WindowDataPtr WindowTree::WindowToWindowData(
     const ServerWindow* window) {
   DCHECK(IsWindowKnown(window));
   const ServerWindow* parent = window->parent();
-  // If the parent isn't known, it means the parent is not visible to us (not
-  // in roots), and should not be sent over.
-  if (parent && !IsWindowKnown(parent))
+  const ServerWindow* transient_parent = window->transient_parent();
+  // If the parent or transient parent isn't known, it means it is not visible
+  // to the client and should not be sent over.
+  if (!IsWindowKnown(parent))
     parent = nullptr;
+  if (!IsWindowKnown(transient_parent))
+    transient_parent = nullptr;
   mojom::WindowDataPtr window_data(mojom::WindowData::New());
   window_data->parent_id =
       parent ? ClientWindowIdForWindow(parent).id : ClientWindowId().id;
   window_data->window_id =
       window ? ClientWindowIdForWindow(window).id : ClientWindowId().id;
+  window_data->transient_parent_id =
+      transient_parent ? ClientWindowIdForWindow(transient_parent).id
+                       : ClientWindowId().id;
   window_data->bounds = window->bounds();
   window_data->properties = mojo::MapToUnorderedMap(window->properties());
   window_data->visible = window->visible();
   return window_data;
 }
 
 void WindowTree::GetWindowTreeImpl(
     const ServerWindow* window,
     std::vector<const ServerWindow*>* windows) const {
   DCHECK(window);
@@ skipping 953 matching lines @@
   client()->OnCompleteDrop(client_window_id.id, event_flags, cursor_offset,
                            effect_bitmask, callback);
 }
 
 void WindowTree::PerformOnDragDropDone() {
   client()->OnDragDropDone();
 }
 
 }  // namespace ws
 }  // namespace ui