MacViews: Don't draw custom frame on Mac

chrome/browser/ui/views/frame/opaque_browser_frame_view.cc

Index: chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
diff --git a/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc b/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
index 830a6445621dd7f01fc1fbf8d3e4ac98f4112efa..1815dea8947f52d17ae09f7f3716cbbba7450272 100644
--- a/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
+++ b/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc
@@ -588,11 +588,9 @@ gfx::Rect OpaqueBrowserFrameView::IconBounds() const {
 }
 
 bool OpaqueBrowserFrameView::ShouldShowWindowTitleBar() const {
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
   // Do not show the custom title bar if the system title bar option is enabled.
   if (!frame()->UseCustomFrame())
     return false;
-#endif
 
   // Do not show caption buttons if the window manager is forcefully providing a
   // title bar (e.g., in Ubuntu Unity, if the window is maximized).