mus: Fix event transformation in client code.

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/Xatom.h>
 #include <X11/Xregion.h>
 #include <X11/Xutil.h>
 #include <X11/extensions/XInput2.h>
@@ skipping 1527 matching lines @@
       gfx::Screen::GetScreen()->GetDisplayNearestWindow(window());
   const gfx::Display display_dest =
       gfx::Screen::GetScreen()->GetDisplayNearestWindow(host->window());
   DCHECK_EQ(display_src.device_scale_factor(),
             display_dest.device_scale_factor());
   gfx::Vector2d offset = GetLocationOnNativeScreen() -
                          host->GetLocationOnNativeScreen();
   gfx::PointF location_in_pixel_in_host =
       located_event->location_f() + gfx::Vector2dF(offset);
   located_event->set_location_f(location_in_pixel_in_host);
+  located_event->set_root_location_f(location_in_pixel_in_host);
 }
 
 void DesktopWindowTreeHostX11::ResetWindowRegion() {
   // If a custom window shape was supplied then apply it.
   if (custom_window_shape_) {
     XShapeCombineRegion(xdisplay_, xwindow_, ShapeBounding, 0, 0,
                         window_shape_.get(), false);
     return;
   }
 
@@ skipping 481 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeThemeAura::instance();
 }
 
 }  // namespace views