x11: Unset the X11 error handlers when the message-loop starts getting destroyed.

chrome/browser/chrome_browser_main_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 "chrome/browser/chrome_browser_main.h"
 
 #include "base/bind.h"
 #include "base/debug/debugger.h"
 #include "base/message_loop.h"
 #include "chrome/browser/browser_shutdown.h"
@@ skipping 49 matching lines @@
   if (!g_in_x11_io_error_handler) {
     g_in_x11_io_error_handler = true;
     LOG(ERROR) << "X IO Error detected";
     browser_shutdown::SetShuttingDownWithoutClosingBrowsers(true);
     browser::SessionEnding();
   }
 
   return 0;
 }
 
+int X11EmptyErrorHandler(Display* d, XErrorEvent* error) {
+  return 0;
+}
+
+int X11EmptyIOErrorHandler(Display* d) {
+  return 0;
+}
+
 }  // namespace
 
 void RecordBreakpadStatusUMA(MetricsService* metrics) {
 #if defined(USE_LINUX_BREAKPAD)
   metrics->RecordBreakpadRegistration(IsCrashReporterEnabled());
 #else
   metrics->RecordBreakpadRegistration(false);
 #endif
   metrics->RecordBreakpadHasDebugger(base::debug::BeingDebugged());
 }
 
 void WarnAboutMinimumSystemRequirements() {
   // Nothing to warn about on X11 right now.
 }
 
 // From browser_main_win.h, stubs until we figure out the right thing...
 
 int DoUninstallTasks(bool chrome_still_running) {
   return content::RESULT_CODE_NORMAL_EXIT;
 }
 
 void SetBrowserX11ErrorHandlers() {
   // Set up error handlers to make sure profile gets written if X server
   // goes away.
   ui::SetX11ErrorHandlers(BrowserX11ErrorHandler, BrowserX11IOErrorHandler);
 }
+
+void UnsetBrowserX11ErrorHandlers() {
+  ui::SetX11ErrorHandlers(X11EmptyErrorHandler, X11EmptyIOErrorHandler);
+}