Widget::ShouldUseNativeFrame is now meaningful on Linux.

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 "base/memory/weak_ptr.h"
 #include "ui/aura/client/activation_change_observer.h"
 #include "ui/aura/client/activation_delegate.h"
@@ skipping 78 matching lines @@
 
   // 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:
   virtual void InitNativeWidget(const Widget::InitParams& params) OVERRIDE;
   virtual NonClientFrameView* CreateNonClientFrameView() OVERRIDE;
   virtual bool ShouldUseNativeFrame() const OVERRIDE;
+  virtual bool ShouldWindowContentsBeTransparent() const OVERRIDE;
   virtual void FrameTypeChanged() OVERRIDE;
   virtual Widget* GetWidget() OVERRIDE;
   virtual const Widget* GetWidget() const OVERRIDE;
   virtual gfx::NativeView GetNativeView() const OVERRIDE;
   virtual gfx::NativeWindow GetNativeWindow() const OVERRIDE;
   virtual Widget* GetTopLevelWidget() OVERRIDE;
   virtual const ui::Compositor* GetCompositor() const OVERRIDE;
   virtual ui::Compositor* GetCompositor() OVERRIDE;
   virtual ui::Layer* GetLayer() OVERRIDE;
   virtual void ReorderNativeViews() OVERRIDE;
@@ skipping 206 matching lines @@
 
   // See class documentation for Widget in widget.h for a note about type.
   Widget::InitParams::Type widget_type_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopNativeWidgetAura);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_