Tracing: re-use JSONTraceDataSink in DevTools' tracing handler...

content/browser/devtools/devtools_io_context.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.
 
 #include <stddef.h>
 
 #include <map>
 
 #include "base/callback.h"
 #include "base/files/file.h"
@@ skipping 10 matching lines @@
     enum Status {
       StatusSuccess,
       StatusEOF,
       StatusFailure
     };
 
     using ReadCallback = base::Callback<
         void(const scoped_refptr<base::RefCountedString>& data, int status)>;
 
     void Read(off_t position, size_t max_size, ReadCallback callback);
-    void Append(const scoped_refptr<base::RefCountedString>& data);
+    void Append(std::unique_ptr<std::string> data);
     const std::string& handle() const { return handle_; }
 
    private:
     Stream();
     ~Stream();
     friend class DevToolsIOContext;
     friend class base::RefCountedDeleteOnMessageLoop<Stream>;
     friend class base::DeleteHelper<Stream>;
 
     void ReadOnFileThread(off_t pos, size_t max_size, ReadCallback callback);
-    void AppendOnFileThread(const scoped_refptr<base::RefCountedString>& data);
+    void AppendOnFileThread(std::unique_ptr<std::string> data);
     bool InitOnFileThreadIfNeeded();
 
     const std::string handle_;
     base::File file_;
     bool had_errors_;
     off_t last_read_pos_;
   };
 
   DevToolsIOContext();
   ~DevToolsIOContext();
 
   scoped_refptr<Stream> CreateTempFileBackedStream();
   scoped_refptr<Stream> GetByHandle(const std::string& handle);
   bool Close(const std::string& handle);
   void DiscardAllStreams();
 
  private:
   using StreamsMap = std::map<std::string, scoped_refptr<Stream>>;
   StreamsMap streams_;
 };
 
 }  // namespace devtools
 }  // namespace content