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

mojo/shell/public/cpp/connect.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_SHELL_PUBLIC_CPP_CONNECT_H_
 #define MOJO_SHELL_PUBLIC_CPP_CONNECT_H_
 
 #include <utility>
 
 #include "mojo/shell/public/interfaces/interface_provider.mojom.h"
 
 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));
   interfaces->GetInterface(Interface::Name_, std::move(pipe.handle1));
 }
 
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_PUBLIC_CPP_CONNECT_H_