DesktopAura: Track windows "owned" via the DesktopWindowTreeHost

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

 // Copyright (c) 2012 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/widget/desktop_aura/desktop_window_tree_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 1164 matching lines @@
 }
 
 bool DesktopWindowTreeHostX11::ShouldUpdateWindowTransparency() const {
   return true;
 }
 
 bool DesktopWindowTreeHostX11::ShouldUseDesktopNativeCursorManager() const {
   return true;
 }
 
+std::vector<DesktopWindowTreeHost*>
+DesktopWindowTreeHostX11::GetOwnedTopLevelHosts() const {
+  return std::vector<DesktopWindowTreeHost*>(window_children_.begin(),

[sky, 2017/01/25 16:41:24]

Do you need to recurse in all these implementations?

[tapted, 2017/01/27 05:34:56]

No - this approach means recursion is only necessary in the implementation of
NativeWidgetPrivate::GetAllOwnedWidgets() which I think reduces complexity
somewhat. Added a comment for GetOwnedTopLevelHosts() so that this is clear.

+                                             window_children_.end());
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopWindowTreeHostX11, aura::WindowTreeHost implementation:
 
 gfx::Transform DesktopWindowTreeHostX11::GetRootTransform() const {
   display::Display display = display::Screen::GetScreen()->GetPrimaryDisplay();
   if (IsVisible()) {
     aura::Window* win = const_cast<aura::Window*>(window());
     display = display::Screen::GetScreen()->GetDisplayNearestWindow(win);
   }
 
@@ skipping 1162 matching lines @@
 
 // static
 DesktopWindowTreeHost* DesktopWindowTreeHost::Create(
     internal::NativeWidgetDelegate* native_widget_delegate,
     DesktopNativeWidgetAura* desktop_native_widget_aura) {
   return new DesktopWindowTreeHostX11(native_widget_delegate,
                                       desktop_native_widget_aura);
 }
 
 }  // namespace views