Widget::ShouldUseNativeFrame is now meaningful on Linux.

ui/views/widget/desktop_aura/desktop_native_widget_aura.cc

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
index dd6a3cf0f80f40648098ab52b72c11c80d00796e..9aab0cb99aee721e7c9c5208857623a3c8655661 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
@@ -1157,7 +1157,13 @@ void DesktopNativeWidgetAura::InstallInputMethodEventFilter() {
 }
 
 void DesktopNativeWidgetAura::UpdateWindowTransparency() {
-  content_window_->SetTransparent(ShouldUseNativeFrame());
+  bool transparent = false;
+#if defined(OS_WIN)
+  // On Windows, a native frame implies Glass, so the window should be
+  // transparent.
+  transparent = ShouldUseNativeFrame();

[sky, 2014/02/03 21:53:03]

Add a method to DesktopRootWindow that determines this rather than ifdefs.

[Matt Giuca, 2014/02/05 23:25:31]

Done.

[sky, 2014/02/06 00:36:14]

This isn't quite what I was asking for. I'm saying add another method to
DesktopRootWindowHost named ShouldContentWindowBeTransparent. This way the
decision is left to the DesktopRootWindowHost and there are no ifdefs in DNWA.
Alternatively move UpdateWindowTransparency to DesktopRootWindowHost.

[Matt Giuca, 2014/02/07 09:13:11]

Done.

+#endif
+  content_window_->SetTransparent(transparent);
 }
 
 }  // namespace views