Notify Desktop::OnHostRezied only when the size has changed or resize is requsted.

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 195 matching lines @@
   // The display and the native X window hosting the desktop.
   Display* xdisplay_;
   ::Window xwindow_;
 
   // Current Aura cursor.
   gfx::NativeCursor current_cursor_;
 
   // The size of |xwindow_|.
   gfx::Rect bounds_;
 
+  // True while we requested configure, but haven't recieved configure event
+  // yet.
+  bool expect_configure_event_;
+
   DISALLOW_COPY_AND_ASSIGN(DesktopHostLinux);
 };
 
 DesktopHostLinux::DesktopHostLinux(const gfx::Rect& bounds)
     : desktop_(NULL),
       xdisplay_(NULL),
       xwindow_(0),
       current_cursor_(aura::kCursorNull),
       bounds_(bounds) {
   // This assumes that the message-pump creates and owns the display.
@@ skipping 76 matching lines @@
     }
     case ConfigureNotify: {
       DCHECK_EQ(xdisplay_, xev->xconfigure.display);
       DCHECK_EQ(xwindow_, xev->xconfigure.window);
       DCHECK_EQ(xwindow_, xev->xconfigure.event);
 
       // It's possible that the X window may be resized by some other means than
       // from within aura (e.g. the X window manager can change the size). Make
       // sure the desktop size is maintained properly.
       gfx::Size size(xev->xconfigure.width, xev->xconfigure.height);
-      if (bounds_.size() != size)
+      if (bounds_.size() != size || expect_configure_event_) {
+        expect_configure_event_ = false;
         bounds_.set_size(size);
-      desktop_->OnHostResized(size);
+        desktop_->OnHostResized(size);
+      }
       handled = true;
       break;
     }
 
     case GenericEvent: {
       ui::TouchFactory* factory = ui::TouchFactory::GetInstance();
       if (!factory->ShouldProcessXI2Event(xev))
         break;
 
       // If this is a motion event we want to coalesce all pending motion
@@ skipping 62 matching lines @@
   XFlush(xdisplay_);
 }
 
 gfx::Size DesktopHostLinux::GetSize() const {
   return bounds_.size();
 }
 
 void DesktopHostLinux::SetSize(const gfx::Size& size) {
   if (bounds_.size() == size)
     return;
+  expect_configure_event_ = true;
   bounds_.set_size(size);
   XResizeWindow(xdisplay_, xwindow_, size.width(), size.height());
 }
 
 void DesktopHostLinux::SetCursor(gfx::NativeCursor cursor) {
   if (current_cursor_ == cursor)
     return;
   current_cursor_ = cursor;
   // Custom web cursors are handled directly.
   if (cursor == kCursorCustom)
@@ skipping 26 matching lines @@
 }
 
 }  // namespace
 
 // static
 DesktopHost* DesktopHost::Create(const gfx::Rect& bounds) {
   return new DesktopHostLinux(bounds);
 }
 
 }  // namespace aura