X11: Wait for UnmapNotify before trying to remap

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/Xatom.h>
 #include <X11/Xregion.h>
 #include <X11/Xutil.h>
 #include <X11/extensions/XInput2.h>
@@ skipping 147 matching lines @@
 // DesktopWindowTreeHostX11, public:
 
 DesktopWindowTreeHostX11::DesktopWindowTreeHostX11(
     internal::NativeWidgetDelegate* native_widget_delegate,
     DesktopNativeWidgetAura* desktop_native_widget_aura)
     : xdisplay_(gfx::GetXDisplay()),
       xwindow_(0),
       x_root_window_(DefaultRootWindow(xdisplay_)),
       atom_cache_(xdisplay_, kAtomsToCache),
       window_mapped_(false),
+      wait_for_unmap_(false),
       is_fullscreen_(false),
       is_always_on_top_(false),
       use_native_frame_(false),
       should_maximize_after_map_(false),
       use_argb_visual_(false),
       drag_drop_client_(NULL),
       native_widget_delegate_(native_widget_delegate),
       desktop_native_widget_aura_(desktop_native_widget_aura),
       content_window_(NULL),
       window_parent_(NULL),
@@ skipping 792 matching lines @@
 
 void DesktopWindowTreeHostX11::ShowImpl() {
   ShowWindowWithState(ui::SHOW_STATE_NORMAL);
   native_widget_delegate_->OnNativeWidgetVisibilityChanged(true);
 }
 
 void DesktopWindowTreeHostX11::HideImpl() {
   if (window_mapped_) {
     XWithdrawWindow(xdisplay_, xwindow_, 0);
     window_mapped_ = false;
+    wait_for_unmap_ = true;
   }
   native_widget_delegate_->OnNativeWidgetVisibilityChanged(false);
 }
 
 gfx::Rect DesktopWindowTreeHostX11::GetBounds() const {
   return bounds_in_pixels_;
 }
 
 void DesktopWindowTreeHostX11::SetBounds(
     const gfx::Rect& requested_bounds_in_pixel) {
@@ skipping 668 matching lines @@
     XChangeProperty(xdisplay_,
                     xwindow_,
                     atom_cache_.GetAtom("_NET_WM_USER_TIME"),
                     XA_CARDINAL,
                     32,
                     PropModeReplace,
                     reinterpret_cast<const unsigned char *>(&wm_user_time_ms),
                     1);
   }
 
+  ui::X11EventSource* event_source = ui::X11EventSource::GetInstance();
+  DCHECK(event_source);
+
+  if (wait_for_unmap_) {
+    // Block until our window is unmapped. This avoids a race condition when
+    // remapping an unmapped window.
+    event_source->BlockUntilWindowUnmapped(xwindow_);
+    DCHECK(!wait_for_unmap_);
+  }
+
   XMapWindow(xdisplay_, xwindow_);
 
   // We now block until our window is mapped. Some X11 APIs will crash and
   // burn if passed |xwindow_| before the window is mapped, and XMapWindow is
   // asynchronous.
-  if (ui::X11EventSource::GetInstance())
-    ui::X11EventSource::GetInstance()->BlockUntilWindowMapped(xwindow_);
+  event_source->BlockUntilWindowMapped(xwindow_);
 }
 
 void DesktopWindowTreeHostX11::SetWindowTransparency() {
   compositor()->SetHostHasTransparentBackground(use_argb_visual_);
   window()->SetTransparent(use_argb_visual_);
   content_window_->SetTransparent(use_argb_visual_);
 }
 
 void DesktopWindowTreeHostX11::Relayout() {
   Widget* widget = native_widget_delegate_->AsWidget();
@@ skipping 211 matching lines @@
       // Some WMs only respect maximize hints after the window has been mapped.
       // Check whether we need to re-do a maximization.
       if (should_maximize_after_map_) {
         Maximize();
         should_maximize_after_map_ = false;
       }
 
       break;
     }
     case UnmapNotify: {
+      wait_for_unmap_ = false;
       FOR_EACH_OBSERVER(DesktopWindowTreeHostObserverX11,
                         observer_list_,
                         OnWindowUnmapped(xwindow_));
       break;
     }
     case ClientMessage: {
       Atom message_type = xev->xclient.message_type;
       if (message_type == atom_cache_.GetAtom("WM_PROTOCOLS")) {
         Atom protocol = static_cast<Atom>(xev->xclient.data.l[0]);
         if (protocol == atom_cache_.GetAtom("WM_DELETE_WINDOW")) {
@@ skipping 137 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeThemeAura::instance();
 }
 
 }  // namespace views