Makes PlatformEventSource creation in Env conditional

ui/aura/bench/bench_main.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.
 
 #if defined(USE_X11)
 #include <X11/Xlib.h>
 #endif
 
 #include "base/at_exit.h"
 #include "base/bind.h"
@@ skipping 286 matching lines @@
   gfx::GLSurface::InitializeOneOff();
 
   // The ContextFactory must exist before any Compositors are created.
   scoped_ptr<ui::InProcessContextFactory> context_factory(
       new ui::InProcessContextFactory());
   ui::ContextFactory::SetInstance(context_factory.get());
 
   base::i18n::InitializeICU();
 
   base::MessageLoopForUI message_loop;
-  aura::Env::CreateInstance();
+  aura::Env::CreateInstance(true);
   scoped_ptr<aura::TestScreen> test_screen(
       aura::TestScreen::CreateFullscreen());
   gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, test_screen.get());
   scoped_ptr<aura::WindowTreeHost> host(
       test_screen->CreateHostForPrimaryDisplay());
   aura::client::SetCaptureClient(
       host->window(),
       new aura::client::DefaultCaptureClient(host->window()));
 
   scoped_ptr<aura::client::FocusClient> focus_client(
@@ skipping 40 matching lines @@
   ui::PrintLayerHierarchy(host->window()->layer(), gfx::Point(100, 100));
 #endif
 
   host->Show();
   base::MessageLoopForUI::current()->Run();
   focus_client.reset();
   host.reset();
 
   return 0;
 }