Pass in the time of the user's last activity timestamp with the NET_ACTIVE_WINDOW event

ui/views/widget/desktop_aura/x11_desktop_handler.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_HANDLER_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_HANDLER_H_
 
 #include <X11/Xlib.h>
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
 #undef RootWindow
@@ skipping 12 matching lines @@
 
 // A singleton that owns global objects related to the desktop and listens for
 // X11 events on the X11 root window. Destroys itself when aura::Env is
 // deleted.
 class VIEWS_EXPORT X11DesktopHandler : public ui::PlatformEventDispatcher,
                                        public aura::EnvObserver {
  public:
   // Returns the singleton handler.
   static X11DesktopHandler* get();
 
+  // Gets/sets the X11 server time of the most recent mouse click, touch or
+  // key press on a Chrome window.
+  int wm_user_time_ms() const {
+    return wm_user_time_ms_;
+  }
+  void set_wm_user_time_ms(unsigned long time_ms) {
+    wm_user_time_ms_ = time_ms;
+  }
+
   // Sends a request to the window manager to activate |window|.
   // This method should only be called if the window is already mapped.
   void ActivateWindow(::Window window);
 
   // Checks if the current active window is |window|.
   bool IsActiveWindow(::Window window) const;
 
   // Processes activation/focus related events. Some of these events are
   // dispatched to the X11 window dispatcher, and not to the X11 root-window
   // dispatcher. The window dispatcher sends these events to here.
@@ skipping 13 matching lines @@
 
   // Handles changes in activation.
   void OnActiveWindowChanged(::Window window);
 
   // The display and the native X window hosting the root window.
   XDisplay* xdisplay_;
 
   // The native root window.
   ::Window x_root_window_;
 
+  // The X11 server time of the most recent mouse click, touch, or key press
+  // on a Chrome window.
+  unsigned long wm_user_time_ms_;
+
   // The activated window.
   ::Window current_window_;
 
   ui::X11AtomCache atom_cache_;
 
   bool wm_supports_active_window_;
 
   DISALLOW_COPY_AND_ASSIGN(X11DesktopHandler);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_HANDLER_H_