Implement system tracing for cros

content/browser/tracing/tracing_ui.h

 // Copyright (c) 2011 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 CONTENT_BROWSER_TRACING_UI_H_
 #define CONTENT_BROWSER_TRACING_UI_H_
 
+#include "base/memory/ref_counted_memory.h"
 #include "content/public/browser/web_ui_controller.h"
 
 namespace content {
 
 // The C++ back-end for the chrome://tracing webui page.
 class CONTENT_EXPORT TracingUI : public WebUIController {
  public:
   explicit TracingUI(WebUI* web_ui);
   virtual ~TracingUI();
   void OnMonitoringStateChanged(bool is_monitoring);
+  void OnSystemTraceDataCollected(
+      const scoped_refptr<base::RefCountedString>& events_str_ptr);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TracingUI);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_TRACING_UI_H_