Change ui::Event::time_stamp from TimeDelta to TimeTicks

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 1424 matching lines @@
 void DesktopWindowTreeHostX11::UpdateWMUserTime(
     const ui::PlatformEvent& event) {
   if (!IsActive())
     return;
 
   ui::EventType type = ui::EventTypeFromNative(event);
   if (type == ui::ET_MOUSE_PRESSED ||
       type == ui::ET_KEY_PRESSED ||
       type == ui::ET_TOUCH_PRESSED) {
     unsigned long wm_user_time_ms = static_cast<unsigned long>(
-        ui::EventTimeFromNative(event).InMilliseconds());
+        (ui::EventTimeFromNative(event) - base::TimeTicks()).InMilliseconds());
     XChangeProperty(xdisplay_,
                     xwindow_,
                     atom_cache_.GetAtom("_NET_WM_USER_TIME"),
                     XA_CARDINAL,
                     32,
                     PropModeReplace,
                     reinterpret_cast<const unsigned char *>(&wm_user_time_ms),
                     1);
     X11DesktopHandler::get()->set_wm_user_time_ms(wm_user_time_ms);
   }
@@ skipping 597 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