Widget::ShouldUseNativeFrame is now meaningful on Linux.

ui/views/widget/native_widget_aura.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/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/client/activation_client.h"
@@ skipping 180 matching lines @@
 
 NonClientFrameView* NativeWidgetAura::CreateNonClientFrameView() {
   return NULL;
 }
 
 bool NativeWidgetAura::ShouldUseNativeFrame() const {
   // There is only one frame type for aura.
   return false;
 }
 
+bool NativeWidgetAura::ShouldWindowContentsBeTransparent() const {
+  return false;
+}
+
 void NativeWidgetAura::FrameTypeChanged() {
   // This is called when the Theme has changed; forward the event to the root
   // widget.
   GetWidget()->ThemeChanged();
   GetWidget()->GetRootView()->SchedulePaint();
 }
 
 Widget* NativeWidgetAura::GetWidget() {
   return delegate_->AsWidget();
 }
@@ skipping 932 matching lines @@
   return aura::Env::GetInstance()->IsMouseButtonDown();
 }
 
 // static
 bool NativeWidgetPrivate::IsTouchDown() {
   return aura::Env::GetInstance()->is_touch_down();
 }
 
 }  // namespace internal
 }  // namespace views