mandoline: write this after lunch.

components/mus/example/mock_sysui/mock_sysui.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_MUS_EXAMPLE_MOCK_SYSUI_MOCK_SYSUI_H_
 #define COMPONENTS_MUS_EXAMPLE_MOCK_SYSUI_MOCK_SYSUI_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "mojo/application/public/cpp/application_delegate.h"
+#include "mojo/services/tracing/public/cpp/tracing_impl.h"
 
 namespace views {
 class AuraInit;
 }
 
 class MockSysUI : public mojo::ApplicationDelegate {
  public:
   MockSysUI();
   ~MockSysUI() override;
 
  private:
   // mojo::ApplicationDelegate:
   void Initialize(mojo::ApplicationImpl* app) override;
   bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override;
 
+  mojo::TracingImpl tracing_;
+
   scoped_ptr<views::AuraInit> aura_init_;
 
   DISALLOW_COPY_AND_ASSIGN(MockSysUI);
 };
 
 #endif  // COMPONENTS_MUS_EXAMPLE_MOCK_SYSUI_MOCK_SYSUI_H_