Eliminate mojo::Shell client lib class

ash/mus/keyboard_ui_mus.h

Index: ash/mus/keyboard_ui_mus.h
diff --git a/ash/mus/keyboard_ui_mus.h b/ash/mus/keyboard_ui_mus.h
index 3ebf826ab3a6d312e30318941ffad73c51153375..c7bcb241e8cef114da54b04546e2b8988c0fca7e 100644
--- a/ash/mus/keyboard_ui_mus.h
+++ b/ash/mus/keyboard_ui_mus.h
@@ -11,7 +11,7 @@
 #include "ui/keyboard/keyboard.mojom.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace ash {
@@ -19,10 +19,10 @@ namespace ash {
 class KeyboardUIMus : public KeyboardUI,
                       public keyboard::mojom::KeyboardObserver {
  public:
-  explicit KeyboardUIMus(mojo::Shell* mojo_shell);
+  explicit KeyboardUIMus(mojo::Connector* connector);
   ~KeyboardUIMus() override;
 
-  static scoped_ptr<KeyboardUI> Create(mojo::Shell* mojo_shell);
+  static scoped_ptr<KeyboardUI> Create(mojo::Connector* connector);
 
   // KeyboardUI:
   void Hide() override;