Aura: delay draw on Expose to avoid getting behind

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 348 matching lines @@
 }
 
 base::MessagePumpDispatcher::DispatchStatus DesktopHostLinux::Dispatch(
     XEvent* xev) {
   bool handled = false;
 
   CheckXEventForConsistency(xev);
 
   switch (xev->type) {
     case Expose:
-      desktop_->Draw();
+      desktop_->ScheduleDraw();
       handled = true;
       break;
     case KeyPress: {
       KeyEvent keydown_event(xev, false);
       handled = desktop_->DispatchKeyEvent(&keydown_event);
       if (ShouldSendCharEventForKeyboardCode(keydown_event.key_code())) {
         KeyEvent char_event(xev, true);
         handled |= desktop_->DispatchKeyEvent(&char_event);
       }
       break;
@@ skipping 229 matching lines @@
   return new DesktopHostLinux(bounds);
 }
 
 // static
 gfx::Size DesktopHost::GetNativeScreenSize() {
   ::Display* xdisplay = base::MessagePumpX::GetDefaultXDisplay();
   return gfx::Size(DisplayWidth(xdisplay, 0), DisplayHeight(xdisplay, 0));
 }
 
 }  // namespace aura