Eliminate mojo::Shell client lib class

components/mus/public/cpp/lib/window_tree_client_impl.cc

Index: components/mus/public/cpp/lib/window_tree_client_impl.cc
diff --git a/components/mus/public/cpp/lib/window_tree_client_impl.cc b/components/mus/public/cpp/lib/window_tree_client_impl.cc
index b1107af04b794a4e0590c88e81cc5192f521b7ab..cdcd7b613a8670b7c973c2d8ac8c887086c01b92 100644
--- a/components/mus/public/cpp/lib/window_tree_client_impl.cc
+++ b/components/mus/public/cpp/lib/window_tree_client_impl.cc
@@ -19,7 +19,7 @@
 #include "components/mus/public/cpp/window_tree_connection_observer.h"
 #include "components/mus/public/cpp/window_tree_delegate.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -80,10 +80,10 @@ Window* BuildWindowTree(WindowTreeClientImpl* client,
 }
 
 WindowTreeConnection* WindowTreeConnection::Create(WindowTreeDelegate* delegate,
-                                                   mojo::Shell* shell) {
+                                                   mojo::Connector* connector) {
   WindowTreeClientImpl* client =
       new WindowTreeClientImpl(delegate, nullptr, nullptr);
-  client->ConnectViaWindowTreeFactory(shell);
+  client->ConnectViaWindowTreeFactory(connector);
   return client;
 }
 
@@ -159,7 +159,7 @@ WindowTreeClientImpl::~WindowTreeClientImpl() {
 }
 
 void WindowTreeClientImpl::ConnectViaWindowTreeFactory(
-    mojo::Shell* shell) {
+    mojo::Connector* connector) {
   // Clients created with no root shouldn't delete automatically.
   delete_on_no_roots_ = false;
 
@@ -167,7 +167,7 @@ void WindowTreeClientImpl::ConnectViaWindowTreeFactory(
   connection_id_ = 101;
 
   mojom::WindowTreeFactoryPtr factory;
-  shell->ConnectToInterface("mojo:mus", &factory);
+  connector->ConnectToInterface("mojo:mus", &factory);
   factory->CreateWindowTree(GetProxy(&tree_ptr_),
                             binding_.CreateInterfacePtrAndBind());
   tree_ = tree_ptr_.get();