Disable textfield's context menu in screen locker

chrome/browser/chromeos/login/screen_locker.cc

Index: chrome/browser/chromeos/login/screen_locker.cc
diff --git a/chrome/browser/chromeos/login/screen_locker.cc b/chrome/browser/chromeos/login/screen_locker.cc
index 4e8b196b6a608231ce5a772cd73a29a98256559f..7971a350e69f77efa928e3683e71592885b6047f 100644
--- a/chrome/browser/chromeos/login/screen_locker.cc
+++ b/chrome/browser/chromeos/login/screen_locker.cc
@@ -806,12 +806,6 @@ void ScreenLocker::Init() {
                               GTK_WINDOW(lock_window_->GetNativeView()));
   g_object_unref(window_group);
 
-  // Don't let X draw default background, which was causing flash on
-  // resume.
-  gdk_window_set_back_pixmap(lock_window_->GetNativeView()->window,
-                             NULL, false);
-  gdk_window_set_back_pixmap(lock_widget_->GetNativeView()->window,
-                             NULL, false);
   lock_window->set_toplevel_focus_widget(
       static_cast<views::WidgetGtk*>(lock_widget_->native_widget())->
           window_contents());