mus: Fix event transformation in client code.

ui/aura/test/x11_event_sender.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 "ui/aura/test/x11_event_sender.h"
 
 #include <X11/Xlib.h>
 
 #include "ui/aura/window_tree_host.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 16 matching lines @@
     case KeyRelease:
     case ButtonPress:
     case ButtonRelease: {
       // The fields used below are in the same place for all of events
       // above. Using xmotion from XEvent's unions to avoid repeating
       // the code.
       event.xmotion.root = DefaultRootWindow(event.xany.display);
       event.xmotion.time = CurrentTime;
 
       gfx::Point point(event.xmotion.x, event.xmotion.y);
-      host->ConvertPointToNativeScreen(&point);
-      event.xmotion.x_root = point.x();
-      event.xmotion.y_root = point.y();
+      gfx::Point root_point = point;
+      host->ConvertPointToNativeScreen(&root_point);
+      event.xmotion.x_root = root_point.x();
+      event.xmotion.y_root = root_point.y();
+      LOG(ERROR) << "Posting at " << point.ToString() << " vs. "
+          << root_point.ToString();
     }
     default:
       break;
   }
   XSendEvent(xdisplay, xwindow, False, 0, &event);
   XFlush(xdisplay);
 }
 
 }  // namespace test
 }  // namespace aura