Widget::ShouldUseNativeFrame is now meaningful on Linux.

ui/views/widget/desktop_aura/desktop_root_window_host_win.cc

Index: ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
diff --git a/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc b/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
index 0952f07f4b658d5afebe5687e68c5f57b5195c81..915e225220e08e848dd1a8268a7dfa53d4ef01cd 100644
--- a/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
+++ b/ui/views/widget/desktop_aura/desktop_root_window_host_win.cc
@@ -373,10 +373,18 @@ void DesktopWindowTreeHostWin::SetVisibilityChangedAnimationsEnabled(
   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();