Remove OS(IOS) and OS(MAC_OS_X) guards.

Tools/DumpRenderTree/chromium/WebViewHost.cpp

 /*
  * Copyright (C) 2010, 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 191 matching lines @@
 {
     return true;
 }
 
 void WebViewHost::showContextMenu(WebFrame*, const WebContextMenuData& contextMenuData)
 {
 }
 
 void WebViewHost::didUpdateLayout()
 {
-#if OS(MAC_OS_X)
+#if OS(DARWIN)
     static bool queryingPreferredSize = false;
     if (queryingPreferredSize)
         return;
 
     queryingPreferredSize = true;
     // Query preferred width to emulate the same functionality in Chromium:
     // see RenderView::CheckPreferredSize (src/content/renderer/render_view.cc)
     // and TabContentsViewMac::RenderViewCreated (src/chrome/browser/tab_contents/tab_contents_view_mac.mm)
     webView()->mainFrame()->contentsPreferredWidth();
     webView()->mainFrame()->documentElementScrollHeight();
@@ skipping 770 matching lines @@
 }
 
 #if ENABLE(MEDIA_STREAM)
 webkit_support::TestMediaStreamClient* WebViewHost::testMediaStreamClient()
 {
     if (!m_testMediaStreamClient.get())
         m_testMediaStreamClient = adoptPtr(new webkit_support::TestMediaStreamClient());
     return m_testMediaStreamClient.get();
 }
 #endif