Revert 177182 - ViewTest.ChangeNativeViewHierarchyFindRoots failure

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 "ui/aura/env_observer.h"
 #include "ui/aura/root_window_host.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_switches.h"
 
 #if defined(USE_X11)
 #include "base/message_pump_aurax11.h"
 #endif
 
 namespace aura {
 
 // static
 Env* Env::instance_ = NULL;
 
 ////////////////////////////////////////////////////////////////////////////////
 // Env, public:
 
 Env::Env()
     : mouse_button_flags_(0),
       is_touch_down_(false),
-      render_white_bg_(true) {
+      render_white_bg_(true),
+      stacking_client_(NULL) {
 }
 
 Env::~Env() {
 #if defined(USE_X11)
   base::MessagePumpAuraX11::Current()->RemoveObserver(
       &device_list_updater_aurax11_);
 #endif
 
   ui::Compositor::Terminate();
 }
@@ skipping 63 matching lines @@
 
 bool Env::CanAcceptEvent(const ui::Event& event) {
   return true;
 }
 
 ui::EventTarget* Env::GetParentTarget() {
   return NULL;
 }
 
 }  // namespace aura