Remove obsolete chromeos specific code

chrome/browser/ui/gtk/gtk_util.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 "chrome/browser/ui/gtk/gtk_util.h"
 
 #include <cairo/cairo.h>
 
 #include <algorithm>
 #include <cstdarg>
@@ skipping 1047 matching lines @@
     gtk_widget_set_size_request(dialog, width, -1);
 }
 
 void PresentWindow(GtkWidget* window, int timestamp) {
   if (timestamp)
     gtk_window_present_with_time(GTK_WINDOW(window), timestamp);
   else
     gtk_window_present(GTK_WINDOW(window));
 }
 
-GtkWindow* GetDialogWindow(GtkWidget* dialog) {
-  return GTK_WINDOW(dialog);
-}
-
 gfx::Rect GetDialogBounds(GtkWidget* dialog) {
   gint x = 0, y = 0, width = 1, height = 1;
   gtk_window_get_position(GTK_WINDOW(dialog), &x, &y);
   gtk_window_get_size(GTK_WINDOW(dialog), &width, &height);
 
   return gfx::Rect(x, y, width, height);
 }
 
 string16 GetStockPreferencesMenuLabel() {
   GtkStockItem stock_item;
@@ skipping 79 matching lines @@
 
 void DoCopy(BrowserWindow* window) {
   DoCutCopyPaste(window, &RenderWidgetHost::Copy, "copy-clipboard");
 }
 
 void DoPaste(BrowserWindow* window) {
   DoCutCopyPaste(window, &RenderWidgetHost::Paste, "paste-clipboard");
 }
 
 }  // namespace gtk_util