Make aura_demo work on Mac

ui/aura/env.h

Index: ui/aura/env.h
diff --git a/ui/aura/env.h b/ui/aura/env.h
index 4d3a477bdb74207d11a18d740a51cedd932a1970..dafc814d8c8bae188775b11bfbe333154a5d8fe6 100644
--- a/ui/aura/env.h
+++ b/ui/aura/env.h
@@ -28,7 +28,7 @@ class InputStateLookup;
 class RootWindow;
 class Window;
 
-#if !defined(OS_MACOSX) && !defined(OS_ANDROID) && !defined(USE_X11)
+#if !defined(OS_ANDROID) && !defined(USE_X11)
 // Creates a platform-specific native event dispatcher.
 base::MessageLoop::Dispatcher* CreateDispatcher();
 #endif
@@ -68,8 +68,7 @@ class AURA_EXPORT Env : public ui::EventTarget {
   // Returns the native event dispatcher. The result should only be passed to
   // base::RunLoop(dispatcher), or used to dispatch an event by
   // |Dispatch(const NativeEvent&)| on it. It must never be stored.
-#if !defined(OS_MACOSX) && !defined(OS_ANDROID) && \
-    !defined(USE_GTK_MESSAGE_PUMP)
+#if defined(USE_AURA)
   base::MessageLoop::Dispatcher* GetDispatcher();
 #endif
 
@@ -96,7 +95,7 @@ class AURA_EXPORT Env : public ui::EventTarget {
   virtual ui::EventTargeter* GetEventTargeter() OVERRIDE;
 
   ObserverList<EnvObserver> observers_;
-#if !defined(OS_MACOSX) && !defined(OS_ANDROID) && !defined(USE_X11)
+#if !defined(OS_ANDROID) && !defined(USE_X11)
   scoped_ptr<base::MessageLoop::Dispatcher> dispatcher_;
 #endif