Eliminate mojo::Shell client lib class

ash/mus/shelf_delegate_mus.cc

Index: ash/mus/shelf_delegate_mus.cc
diff --git a/ash/mus/shelf_delegate_mus.cc b/ash/mus/shelf_delegate_mus.cc
index 65dc48820a37ac0661c89ea5814c0c16b9f7ceeb..0b9a95ee904ce0e436acf4c8b9b712fdb8fb14c7 100644
--- a/ash/mus/shelf_delegate_mus.cc
+++ b/ash/mus/shelf_delegate_mus.cc
@@ -10,7 +10,7 @@
 #include "ash/shell.h"
 #include "base/strings/string_util.h"
 #include "mojo/common/common_type_converters.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/resources/grit/ui_resources.h"
 #include "ui/views/mus/window_manager_connection.h"
@@ -83,8 +83,9 @@ class ShelfItemDelegateMus : public ShelfItemDelegate {
 
 ShelfDelegateMus::ShelfDelegateMus(ShelfModel* model)
     : model_(model), binding_(this) {
-  mojo::Shell* shell = views::WindowManagerConnection::Get()->shell();
-  shell->ConnectToInterface("mojo:desktop_wm", &user_window_controller_);
+  mojo::Connector* connector =
+      views::WindowManagerConnection::Get()->connector();
+  connector->ConnectToInterface("mojo:desktop_wm", &user_window_controller_);
   user_window_controller_->AddUserWindowObserver(
       binding_.CreateInterfacePtrAndBind());
 }