Widget::ShouldUseNativeFrame is now meaningful on Linux.

ui/views/widget/desktop_aura/desktop_root_window_host.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_ROOT_WINDOW_HOST_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_ROOT_WINDOW_HOST_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/ui_base_types.h"
@@ skipping 107 matching lines @@
   virtual void ClearNativeFocus() = 0;
 
   virtual Widget::MoveLoopResult RunMoveLoop(
       const gfx::Vector2d& drag_offset,
       Widget::MoveLoopSource source,
       Widget::MoveLoopEscapeBehavior escape_behavior) = 0;
   virtual void EndMoveLoop() = 0;
 
   virtual void SetVisibilityChangedAnimationsEnabled(bool value) = 0;
 
-  virtual bool ShouldUseNativeFrame() = 0;
+  // Determines whether the window should use native title bar and borders.
+  virtual bool ShouldUseNativeFrame() const = 0;
+  // Determines whether the window contents should be rendered transparently
+  // (for example, so that they can overhang onto the window title bar).
+  virtual bool ShouldWindowContentsBeTransparent() const = 0;
   virtual void FrameTypeChanged() = 0;
   virtual NonClientFrameView* CreateNonClientFrameView() = 0;
 
   virtual void SetFullscreen(bool fullscreen) = 0;
   virtual bool IsFullscreen() const = 0;
 
   virtual void SetOpacity(unsigned char opacity) = 0;
 
   virtual void SetWindowIcons(const gfx::ImageSkia& window_icon,
                               const gfx::ImageSkia& app_icon) = 0;
@@ skipping 10 matching lines @@
   virtual void OnNativeWidgetBlur() = 0;
 
   // Returns true if the Widget was closed but is still showing because of
   // animations.
   virtual bool IsAnimatingClosed() const = 0;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_ROOT_WINDOW_HOST_H_