Revert of Revert of ui::PlatformWindowDelegate::OnClosed() isn't called when a ui::X11Window is closed

ui/platform_window/x11/x11_window.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/platform_window/x11/x11_window.h"
 
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
@@ skipping 38 matching lines @@
       window_mapped_(false) {
   CHECK(delegate_);
   TouchFactory::SetTouchDeviceListFromCommandLine();
 }
 
 X11Window::~X11Window() {
   Destroy();
 }
 
 void X11Window::Destroy() {
+  delegate_->OnClosed();
   if (xwindow_ == None)
     return;
 
   // Stop processing events.
   PlatformEventSource::GetInstance()->RemovePlatformEventDispatcher(this);
   XDestroyWindow(xdisplay_, xwindow_);
   xwindow_ = None;
 }
 
 void X11Window::ProcessXInput2Event(XEvent* xev) {
@@ skipping 281 matching lines @@
 
     case GenericEvent: {
       ProcessXInput2Event(xev);
       break;
     }
   }
   return POST_DISPATCH_STOP_PROPAGATION;
 }
 
 }  // namespace ui