Remove unnecessary uses of aura::Env::GetDispatcher

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"
@@ skipping 75 matching lines @@
 
 void Env::RootWindowActivated(RootWindow* root_window) {
   FOR_EACH_OBSERVER(EnvObserver, observers_,
                     OnRootWindowActivated(root_window));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Env, private:
 
 void Env::Init() {
-#if !defined(OS_MACOSX) && !defined(OS_ANDROID) && !defined(USE_X11) && \
-    !defined(USE_OZONE)
+#if defined(OS_WIN)
   dispatcher_.reset(CreateDispatcher());
 #endif
 #if defined(USE_X11)
   // We can't do this with a root window listener because XI_HierarchyChanged
   // messages don't have a target window.
   base::MessagePumpX11::Current()->AddObserver(
       &device_list_updater_aurax11_);
 #endif
   ui::Compositor::Initialize();
 }
@@ skipping 22 matching lines @@
 scoped_ptr<ui::EventTargetIterator> Env::GetChildIterator() const {
   return scoped_ptr<ui::EventTargetIterator>();
 }
 
 ui::EventTargeter* Env::GetEventTargeter() {
   NOTREACHED();
   return NULL;
 }
 
 }  // namespace aura