Have content/ create and destroy its own threads.

chrome/browser/chromeos/login/screen_locker_webui.cc

Index: chrome/browser/chromeos/login/screen_locker_webui.cc
diff --git a/chrome/browser/chromeos/login/screen_locker_webui.cc b/chrome/browser/chromeos/login/screen_locker_webui.cc
index 00504a0c9d2ec5ab7c8e7396ef7f83cfaa895a9e..e32fffb6477635e8d5b42828021492c2d04f34ce 100644
--- a/chrome/browser/chromeos/login/screen_locker_webui.cc
+++ b/chrome/browser/chromeos/login/screen_locker_webui.cc
@@ -4,15 +4,6 @@
 
 #include "chrome/browser/chromeos/login/screen_locker_webui.h"
 
-#include <X11/extensions/XTest.h>
-#include <X11/keysym.h>
-#include <gdk/gdkkeysyms.h>
-#include <gdk/gdkx.h>
-
-// Evil hack to undo X11 evil #define.
-#undef None
-#undef Status
-
 #include "base/command_line.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
@@ -24,6 +15,12 @@
 #include "ui/gfx/screen.h"
 #include "views/widget/native_widget_gtk.h"
 
+// These conflict with base/tracked_objects.h, so must come last.
+#include <X11/extensions/XTest.h>
+#include <X11/keysym.h>
+#include <gdk/gdkkeysyms.h>
+#include <gdk/gdkx.h>
+
 namespace {
 
 chromeos::ScreenLockerWebUI* screen_locker_webui_ = NULL;