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

mojo/shell/public/interfaces/interface_provider.mojom

 // 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.
 
-module mojo;
+module mojo.shell.mojom;
 
 // An interface through which a client may request interfaces from a host.
 // Instances of this interface are created within the context of an
 // already-identified client and host pair, so there is no need to explicitly
 // identify the client or host in the methods below.
 interface InterfaceProvider {
   // Asks the host to provide an implementation of the interface identified by
   // |interface_name| through the message |pipe| endpoint supplied by the caller.
   // If the host is not willing or able to provide the requested interface, it
   // must close the |pipe|.
   GetInterface(string interface_name, handle<message_pipe> pipe);
 };