DesktopAura: Track windows "owned" via the DesktopWindowTreeHost

ui/views/mus/desktop_window_tree_host_mus.cc

 // Copyright 2016 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 "ui/views/mus/desktop_window_tree_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/cursor_client.h"
@@ skipping 649 matching lines @@
 bool DesktopWindowTreeHostMus::ShouldUpdateWindowTransparency() const {
   // Needed so the window manager can render the client decorations.
   return false;
 }
 
 bool DesktopWindowTreeHostMus::ShouldUseDesktopNativeCursorManager() const {
   // We manage the cursor ourself.
   return false;
 }
 
+std::vector<DesktopWindowTreeHost*>
+DesktopWindowTreeHostMus::GetOwnedTopLevelHosts() const {
+  return std::vector<DesktopWindowTreeHost*>(children_.begin(),
+                                             children_.end());
+}
+
 void DesktopWindowTreeHostMus::OnWindowManagerFrameValuesChanged() {
   NonClientView* non_client_view =
       native_widget_delegate_->AsWidget()->non_client_view();
   if (non_client_view) {
     non_client_view->Layout();
     non_client_view->SchedulePaint();
   }
 
   SendClientAreaToServer();
   SendHitTestMaskToServer();
@@ skipping 50 matching lines @@
     aura::client::FocusClient* focus_client,
     aura::Window* window) {
   if (window == this->window()) {
     desktop_native_widget_aura_->HandleActivationChanged(true);
   } else if (is_active_) {
     desktop_native_widget_aura_->HandleActivationChanged(false);
   }
 }
 
 }  // namespace views