Use ShellPtr type in ApplicationLoader instead of untyped handles

shell/application_manager/application_loader.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 SHELL_APPLICATION_MANAGER_APPLICATION_LOADER_H_
 #define SHELL_APPLICATION_MANAGER_APPLICATION_LOADER_H_
 
 #include "base/callback.h"
 #include "mojo/public/cpp/system/core.h"
+#include "mojo/public/interfaces/application/shell.mojom.h"
 #include "mojo/services/network/public/interfaces/url_loader.mojom.h"
 #include "shell/application_manager/application_manager_export.h"
 #include "url/gurl.h"
 
 namespace mojo {
 
 class ApplicationManager;
 
 // Interface to allowing loading behavior to be established for schemes,
 // specific urls or as the default.
@@ skipping 15 matching lines @@
   //
   // 1. |url| can refer directly to a Mojo application. In this case,
   //    shell_handle should be used to implement the mojo.Application interface.
   //
   // 2. |url| can refer to some content that can be handled by some other Mojo
   //    application. In this case, call callbacks and specify the URL of the
   //    application that should handle the content.  The specified application
   //    must implement the mojo.ContentHandler interface.
   virtual void Load(ApplicationManager* application_manager,
                     const GURL& url,
-                    ScopedMessagePipeHandle shell_handle,
+                    ShellPtr shell,
                     LoadCallback callback) = 0;
 
   // Called when the Application exits.
   virtual void OnApplicationError(ApplicationManager* manager,
                                   const GURL& url) = 0;
 
  protected:
   ApplicationLoader() {}
 };
 
 }  // namespace mojo
 
 #endif  // SHELL_APPLICATION_MANAGER_APPLICATION_LOADER_H_