Internalize JSON chunk management to trace_event.h API.

content/browser/trace_subscriber_stdio.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_TRACE_SUBSCRIBER_STDIO_H_
 #define CONTENT_BROWSER_TRACE_SUBSCRIBER_STDIO_H_
 #pragma once
 
 #include <string>
 
@@ skipping 11 matching lines @@
   // Creates or overwrites the specified file. Returns true on success.
   bool OpenFile(const FilePath& path);
   // Finishes json output and closes file.
   void CloseFile();
 
   // Returns TRUE if we're currently writing data to a file.
   bool IsValid();
 
   // Implementation of TraceSubscriber
   virtual void OnEndTracingComplete();
-  virtual void OnTraceDataCollected(const std::string& json_events);
+  virtual void OnTraceDataCollected(const std::string& trace_fragment);
 
   virtual ~TraceSubscriberStdio();
 
  private:
   FILE* file_;
+  base::debug::TraceResultBuffer trace_buffer_;
 };
 
 #endif  // CONTENT_BROWSER_TRACE_SUBSCRIBER_STDIO_H_