Widget::ShouldUseNativeFrame is now meaningful on Linux.

ui/views/widget/desktop_aura/desktop_root_window_host_win.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/views/widget/desktop_aura/desktop_root_window_host_win.h"
 
 #include "base/win/metro.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 355 matching lines @@
 void DesktopWindowTreeHostWin::EndMoveLoop() {
   message_handler_->EndMoveLoop();
 }
 
 void DesktopWindowTreeHostWin::SetVisibilityChangedAnimationsEnabled(
     bool value) {
   message_handler_->SetVisibilityChangedAnimationsEnabled(value);
   content_window_->SetProperty(aura::client::kAnimationsDisabledKey, !value);
 }
 
-bool DesktopWindowTreeHostWin::ShouldUseNativeFrame() {
+bool DesktopWindowTreeHostWin::ShouldUseNativeFrame() const {
   return ui::win::IsAeroGlassEnabled();
 }
 
+bool DesktopWindowTreeHostWin::ShouldWindowContentsBeTransparent() const {
+  // If the window has a native frame, we assume it is an Aero Glass window, and
+  // is therefore transparent. Note: This is not equivalent to calling
+  // IsAeroGlassEnabled, because ShouldUseNativeFrame is overridden in a
+  // subclass.
+  return ShouldUseNativeFrame();
+}
+
 void DesktopWindowTreeHostWin::FrameTypeChanged() {
   message_handler_->FrameTypeChanged();
   SetWindowTransparency();
 }
 
 NonClientFrameView* DesktopWindowTreeHostWin::CreateNonClientFrameView() {
   return GetWidget()->ShouldUseNativeFrame() ?
       new NativeFrameView(GetWidget()) : NULL;
 }
 
@@ skipping 617 matching lines @@
 
 // static
 DesktopWindowTreeHost* DesktopWindowTreeHost::Create(
     internal::NativeWidgetDelegate* native_widget_delegate,
     DesktopNativeWidgetAura* desktop_native_widget_aura) {
   return new DesktopWindowTreeHostWin(native_widget_delegate,
                                       desktop_native_widget_aura);
 }
 
 }  // namespace views