linux: Fixes a racy crash by key input at termination.

chrome/browser/ui/libgtk2ui/gtk2_event_loop.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 "chrome/browser/ui/libgtk2ui/gtk2_event_loop.h"
 
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
 #include <gtk/gtk.h>
 #include <X11/X.h>
 
 #include "base/memory/singleton.h"
 #include "ui/gfx/x/x11_types.h"
 
 namespace libgtk2ui {
 
 // static
 Gtk2EventLoop* Gtk2EventLoop::GetInstance() {
   return Singleton<Gtk2EventLoop>::get();
 }
 
 Gtk2EventLoop::Gtk2EventLoop() {
-  gdk_event_handler_set(GdkEventTrampoline, this, NULL);
+  gdk_event_handler_set(DispatchGdkEvent, NULL, NULL);
 }
 
 Gtk2EventLoop::~Gtk2EventLoop() {
   gdk_event_handler_set(reinterpret_cast<GdkEventFunc>(gtk_main_do_event),
                         NULL, NULL);
 }
 
 // static
-void Gtk2EventLoop::GdkEventTrampoline(GdkEvent* event, gpointer data) {
-  Gtk2EventLoop* loop = reinterpret_cast<Gtk2EventLoop*>(data);
-  loop->DispatchGdkEvent(event);
-}
-
-void Gtk2EventLoop::DispatchGdkEvent(GdkEvent* gdk_event) {
+void Gtk2EventLoop::DispatchGdkEvent(GdkEvent* gdk_event, gpointer) {
   switch (gdk_event->type) {
     case GDK_KEY_PRESS:
     case GDK_KEY_RELEASE:
       ProcessGdkEventKey(gdk_event->key);
       break;
     default:
       break;  // Do nothing.
   }
 
   gtk_main_do_event(gdk_event);
 }
 
+// static
 void Gtk2EventLoop::ProcessGdkEventKey(const GdkEventKey& gdk_event_key) {
   // This function translates GdkEventKeys into XKeyEvents and puts them to
   // the X event queue.
   //
   // base::MessagePumpX11 is using the X11 event queue and all key events should
   // be processed there.  However, there are cases(*1) that GdkEventKeys are
   // created instead of XKeyEvents.  In these cases, we have to translate
   // GdkEventKeys to XKeyEvents and puts them to the X event queue so our main
   // event loop can handle those key events.
   //
@@ skipping 11 matching lines @@
   x_event.xkey.root = DefaultRootWindow(x_event.xkey.display);
   x_event.xkey.time = gdk_event_key.time;
   x_event.xkey.state = gdk_event_key.state;
   x_event.xkey.keycode = gdk_event_key.hardware_keycode;
   x_event.xkey.same_screen = true;
 
   XPutBackEvent(x_event.xkey.display, &x_event);
 }
 
 }  // namespace libgtk2ui