X11: Add missing initialization for window state list

This is a followup to:
https://chromium.googlesource.com/chromium/src.git/+/270b2bfa01f4eadfe6f25673767a3357158e0ef9

BUG=856607
R=sadrul
CC=fbeaufort

Change-Id: If06c971a309b4630e44184f7a08bb156b620c7ec
Reviewed-on: https://chromium-review.googlesource.com/1123367
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572311}

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

@@ -1549,6 +1549,8 @@ void DesktopWindowTreeHostX11::InitX11Window(
   // SetWMSpecState) has no effect here since the window has not yet been
   // mapped. So we manually change the state.
   if (!state_atom_list.empty()) {
+    DCHECK(window_properties_in_client_.empty());
+    window_properties_in_client_ = state_atom_list;
     ui::SetAtomArrayProperty(xwindow_,
                              "_NET_WM_STATE",
                              "ATOM",