mandoline: write this after lunch.

components/filesystem/file_system_app.h

 // Copyright 2015 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 COMPONENTS_FILESYSTEM_FILE_SYSTEM_APP_H_
 #define COMPONENTS_FILESYSTEM_FILE_SYSTEM_APP_H_
 
 #include "base/macros.h"
 #include "components/filesystem/directory_impl.h"
 #include "components/filesystem/file_system_impl.h"
 #include "components/filesystem/public/interfaces/file_system.mojom.h"
 #include "mojo/application/public/cpp/application_delegate.h"
 #include "mojo/application/public/cpp/interface_factory.h"
+#include "mojo/services/tracing/public/cpp/tracing_impl.h"
 
 namespace mojo {
 class ApplicationImpl;
 }
 
 namespace filesystem {
 
 class FileSystemApp : public mojo::ApplicationDelegate,
                       public mojo::InterfaceFactory<FileSystem> {
  public:
@@ skipping 28 matching lines @@
     ~Client();
 
     Client& operator=(Client&& rhs);
 
     DirectoryImpl* directory_;
     FileSystemClientPtr fs_client_;
   };
   std::vector<Client> client_mapping_;
 
   mojo::ApplicationImpl* app_;
+  mojo::TracingImpl tracing_;
 
   // Set to true when our shell connection is closed. On connection error, we
   // then broadcast a notification to all FileSystemClients that they should
   // shut down. Once the final one does, then we QuitNow().
   bool in_shutdown_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemApp);
 };
 
 }  // namespace filesystem
 
 #endif  // COMPONENTS_FILESYSTEM_FILE_SYSTEM_APP_H_