Move InterfaceProvider into the shell::mojom namespace like the rest of the shell interfaces.

mojo/shell/public/cpp/connect.h

Index: mojo/shell/public/cpp/connect.h
diff --git a/mojo/shell/public/cpp/connect.h b/mojo/shell/public/cpp/connect.h
index 48d76a8839cb578035b31d54d6d30f00830c9426..b0493216358ea20bc7079b598310d45f1dc0ea01 100644
--- a/mojo/shell/public/cpp/connect.h
+++ b/mojo/shell/public/cpp/connect.h
@@ -13,7 +13,7 @@ namespace mojo {
 
 // Binds |ptr| to a remote implementation of Interface from |interfaces|.
 template <typename Interface>
-inline void GetInterface(InterfaceProvider* interfaces,
+inline void GetInterface(shell::mojom::InterfaceProvider* interfaces,
                          InterfacePtr<Interface>* ptr) {
   MessagePipe pipe;
   ptr->Bind(InterfacePtrInfo<Interface>(std::move(pipe.handle0), 0u));