Couple of fixes for DesktopWindowTreeHostMus.

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 72 matching lines @@
   // as by the time we get here |dispatcher_| is NULL.
   virtual void OnDesktopWindowTreeHostDestroyed(aura::WindowTreeHost* host);
 
   wm::CompoundEventFilter* root_window_event_filter() {
     return root_window_event_filter_.get();
   }
   aura::WindowTreeHost* host() {
     return host_.get();
   }
 
+  aura::Window* content_window() { return content_window_; }
+
   // Ensures that the correct window is activated/deactivated based on whether
   // we are being activated/deactivated.
   void HandleActivationChanged(bool active);
 
  protected:
   // Overridden from internal::NativeWidgetPrivate:
   void InitNativeWidget(const Widget::InitParams& params) override;
   void OnWidgetInitDone() override;
   NonClientFrameView* CreateNonClientFrameView() override;
   bool ShouldUseNativeFrame() const override;
@@ skipping 205 matching lines @@
   // The following factory is used for calls to close the NativeWidgetAura
   // instance.
   base::WeakPtrFactory<DesktopNativeWidgetAura> close_widget_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopNativeWidgetAura);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_