X11: Fix task manager able to resize to 1x1px

ui/views/widget/desktop_aura/desktop_window_tree_host_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 "ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 1894 matching lines @@
       show_state != ui::SHOW_STATE_NORMAL &&
       show_state != ui::SHOW_STATE_INACTIVE &&
       show_state != ui::SHOW_STATE_MAXIMIZED) {
     // It will behave like SHOW_STATE_NORMAL.
     NOTIMPLEMENTED();
   }
 
   // Before we map the window, set size hints. Otherwise, some window managers
   // will ignore toplevel XMoveWindow commands.
   XSizeHints size_hints;
-  size_hints.flags = PPosition;
+  size_hints.flags = 0;
+  long supplied_return;
+  XGetWMNormalHints(xdisplay_, xwindow_, &size_hints, &supplied_return);
+  size_hints.flags |= PPosition;
   size_hints.x = bounds_in_pixels_.x();
   size_hints.y = bounds_in_pixels_.y();
   XSetWMNormalHints(xdisplay_, xwindow_, &size_hints);
 
   // If SHOW_STATE_INACTIVE, tell the window manager not to focus the window
   // when mapping. This is done by setting the _NET_WM_USER_TIME to 0. See e.g.
   // http://standards.freedesktop.org/wm-spec/latest/ar01s05.html
   ignore_keyboard_input_ = show_state == ui::SHOW_STATE_INACTIVE;
   unsigned long wm_user_time_ms =
       ignore_keyboard_input_
@@ skipping 425 matching lines @@
 
 // static
 DesktopWindowTreeHost* DesktopWindowTreeHost::Create(
     internal::NativeWidgetDelegate* native_widget_delegate,
     DesktopNativeWidgetAura* desktop_native_widget_aura) {
   return new DesktopWindowTreeHostX11(native_widget_delegate,
                                       desktop_native_widget_aura);
 }
 
 }  // namespace views