aura: Try to make Linux host resize code more reliable.

ui/aura/desktop_host_linux.cc

 // Copyright (c) 2011 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/aura/desktop_host.h"
 
 #include <X11/cursorfont.h>
 #include <X11/Xlib.h>
 
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
@@ skipping 359 matching lines @@
   desktop_ = desktop;
 }
 
 gfx::AcceleratedWidget DesktopHostLinux::GetAcceleratedWidget() {
   return xwindow_;
 }
 
 void DesktopHostLinux::Show() {
   XMapWindow(xdisplay_, xwindow_);
 
+  // Wait for notification that the window is mapped, which happens
+  // asynchronously if there's a window manager running.  Ideally we wouldn't
+  // need to wait for this, but some window managers don't do anything to let us
+  // know that they're there (*cough*ion3*cough*), in which case we need to make
+  // sure that the window is mapped before sending a SetInputFocus request.
+  while (true) {
+    XEvent event;
+    XWindowEvent(xdisplay_, xwindow_, StructureNotifyMask, &event);
+    if (event.type == MapNotify)
+      break;
+  }
+
   // If there's no window manager running, we need to assign the X input focus
-  // to our host window.  (If there's no window manager running, it should also
-  // be safe to assume that the host window will have been mapped by the time
-  // that our SetInputFocus request is received.)
-  if (!IsWindowManagerPresent())
+  // to our host window.
+  if (!IsWindowManagerPresent()) {
     XSetInputFocus(xdisplay_, xwindow_, RevertToNone, CurrentTime);
-
-  XFlush(xdisplay_);
+    XFlush(xdisplay_);
+  }
 }
 
 gfx::Size DesktopHostLinux::GetSize() const {
   return bounds_.size();
 }
 
 void DesktopHostLinux::SetSize(const gfx::Size& size) {
   if (bounds_.size() == size)
     return;
   bounds_.set_size(size);
@@ skipping 35 matching lines @@
 }
 
 }  // namespace
 
 // static
 DesktopHost* DesktopHost::Create(const gfx::Rect& bounds) {
   return new DesktopHostLinux(bounds);
 }
 
 }  // namespace aura