Make aura_demo work on Mac

ui/aura/env.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 "ui/aura/env.h"
 
 #include "base/command_line.h"
+#include "base/message_loop/message_pump_dispatcher.h"
 #include "ui/aura/env_observer.h"
 #include "ui/aura/input_state_lookup.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_switches.h"
 #include "ui/events/event_target_iterator.h"
 
 #if defined(USE_X11)
 #include "base/message_loop/message_pump_x11.h"
 #endif
@@ skipping 50 matching lines @@
 
 void Env::RemoveObserver(EnvObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 bool Env::IsMouseButtonDown() const {
   return input_state_lookup_.get() ? input_state_lookup_->IsMouseButtonDown() :
       mouse_button_flags_ != 0;
 }
 
-#if !defined(OS_MACOSX) && !defined(OS_ANDROID) && \
-    !defined(USE_GTK_MESSAGE_PUMP)
 base::MessageLoop::Dispatcher* Env::GetDispatcher() {
 #if defined(USE_X11)
   return base::MessagePumpX11::Current();
 #else
   return dispatcher_.get();
 #endif
 }
-#endif
 
 void Env::RootWindowActivated(RootWindow* root_window) {
   FOR_EACH_OBSERVER(EnvObserver, observers_,
                     OnRootWindowActivated(root_window));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Env, private:
 
 void Env::Init() {
@@ skipping 34 matching lines @@
 scoped_ptr<ui::EventTargetIterator> Env::GetChildIterator() const {
   return scoped_ptr<ui::EventTargetIterator>();
 }
 
 ui::EventTargeter* Env::GetEventTargeter() {
   NOTREACHED();
   return NULL;
 }
 
 }  // namespace aura