Eliminate mojo::Shell client lib class

ui/views/mus/platform_window_mus.h

Index: ui/views/mus/platform_window_mus.h
diff --git a/ui/views/mus/platform_window_mus.h b/ui/views/mus/platform_window_mus.h
index 5cc440b02d29fabf3b58a70f53cafde9ae0292bb..2d95a2163935b38be55486b0bbefb9b7ba1633e4 100644
--- a/ui/views/mus/platform_window_mus.h
+++ b/ui/views/mus/platform_window_mus.h
@@ -21,7 +21,7 @@ class BitmapUploader;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace ui {
@@ -36,7 +36,7 @@ class VIEWS_MUS_EXPORT PlatformWindowMus
       public NON_EXPORTED_BASE(mus::InputEventHandler) {
  public:
   PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
-                    mojo::Shell* shell,
+                    mojo::Connector* connector,
                     mus::Window* mus_window);
   ~PlatformWindowMus() override;