Update the window shape when toggling whether the system titlebar and borders are used on KDE

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
index ced380dc42d43c0cc9a09035944ae1172f75e183..8a612a1068f757aba38d1a10337fe8fe01616249 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
@@ -349,10 +349,8 @@ aura::WindowTreeHost* DesktopWindowTreeHostX11::AsWindowTreeHost() {
 
 void DesktopWindowTreeHostX11::ShowWindowWithState(
     ui::WindowShowState show_state) {
-  if (!window_mapped_) {
+  if (!window_mapped_)
     MapWindow(show_state);
-    ResetWindowRegion();
-  }
 
   if (show_state == ui::SHOW_STATE_NORMAL ||
       show_state == ui::SHOW_STATE_MAXIMIZED) {
@@ -1274,6 +1272,7 @@ bool DesktopWindowTreeHostX11::HasWMSpecProperty(const char* property) const {
 void DesktopWindowTreeHostX11::SetUseNativeFrame(bool use_native_frame) {
   use_native_frame_ = use_native_frame;
   x11_window_event_filter_->SetUseHostWindowBorders(use_native_frame);
+  ResetWindowRegion();

[pkotwicz, 2014/06/10 22:00:53]

I am unsure if XShapeCombineRectangles() is safe to call on an unmapped window
in all window managers. If does not crash on either KDE or Cinnamon.

 }
 
 void DesktopWindowTreeHostX11::OnCaptureReleased() {